Bioactive Compounds and the Organoleptic Characteristics of Functional Foods: Mechanisms and Technological Innovations

Abstract

Functional foods are designed to provide health benefits beyond basic nutrition; however, the incorporation of bioactive compounds often impacts flavor, stability, and consumer acceptance, making flavor science a critical challenge in product development. This review explores the biochemical and biotechnological mechanisms underlying the formation and modulation of flavor in functional foods. Advances in biotechnology, including microbial fermentation, enzyme engineering, biocatalyst immobilization, and metabolic optimization, have facilitated the sustainable production of natural flavor compounds with improved sensory profiles. Emerging technologies, including nanoencapsulation, ultrasound-assisted extraction, nanotechnology, artificial intelligence-driven flavor design, and 3D food printing, are also discussed for their roles in enhancing the stability, bioavailability, and controlled release of bioactive and flavor compounds. By integrating biotechnology and flavor science, these approaches offer promising strategies for developing clean-label, sensory-optimized functional foods that meet nutritional needs while satisfying consumer expectations, thereby driving innovation toward healthier and more sustainable food systems.

1. Introduction

Functional foods have emerged as a pivotal concept at the intersection of nutrition, health, and food science, providing benefits that extend beyond basic nutrition by positively influencing physiological functions and reducing the risk of chronic diseases [1,2]. These foods are typically classified into two categories: those naturally rich in bioactive compounds, such as fruits, vegetables, and whole grains, and those fortified with extracted or purified bioactive compounds, including carotenoid-enriched snacks and fortified beverages [3]. The incorporation of bioactive compounds, derived from plants or microorganisms recognized as generally regarded as safe (GRAS), aims to enhance the nutritional value and functional properties of food products [4,5].

Bioactive compounds, such as vitamins, polyphenols, flavonoids, carotenoids, peptides, and dietary fibers, contribute to the prevention and management of non-communicable diseases, including cardiovascular disorders, diabetes, and certain cancers [6,7]. Increasingly, research has focused on using food processing by-products, such as fruit peels, seeds, and pomace, as sustainable sources of bioactive compounds, providing opportunities for value addition and waste valorization [8,9].

Flavor is a key determinant of functional food acceptance and success, influencing consumer choice and compliance. Both volatile and non-volatile flavor compounds are formed through complex biochemical pathways [10,11], which are tightly regulated by genetic, enzymatic, and environmental factors. Advances in metabolic engineering, microbial fermentation, and enzyme optimization have enabled the enhanced production of diverse flavor compounds, supporting the development of functional foods with improved sensory attributes and health benefits [12,13].

Technological innovations, including enzyme immobilization, encapsulation, supercritical fluid extraction, ultrasound-assisted extraction, nanotechnology, and precision fermentation, have further enabled the stabilization, bioavailability, and controlled delivery of bioactive and flavor compounds, ensuring their effectiveness in complex food matrices [14,15,16,17]. Moreover, emerging digital tools, such as artificial intelligence (AI) and big data analytics, are transforming the optimization of flavor and bioactive compounds, offering tailored solutions that align with consumer preferences and sustainability goals [18,19].

Although the formation of bioactive compounds and flavor has been extensively studied, research rarely integrates mechanistic insights into flavor formation with emerging technological innovations. Studies often examine bioactive composition and sensory attributes separately, and the effects of advanced processing techniques, such as ultrasound, AI-driven formulation, 3D food printing, and nanotechnology, on organoleptic quality remain insufficiently explored. This review addresses these gaps by linking the molecular mechanisms underlying flavor formation with innovative strategies to preserve and enhance bioactive compounds, providing a coherent framework to guide the development of functional foods. Furthermore, it offers a comprehensive overview of functional foods, including their sources, biochemical pathways, and technological strategies for producing bioactive and flavor compounds, while highlighting recent advances in processing technologies that simultaneously enhance health benefits, sensory quality, and industrial applicability.

2. Bioactive Compounds in Functional Foods

Functional foods are commonly defined as whole, fortified, enriched, or enhanced foods that provide health benefits beyond basic nutrition when consumed regularly and in effective amounts as part of a balanced and varied diet [3,20]. Although fruits, vegetables, cereals, and legumes naturally contain a wide range of bioactive compounds, their endogenous concentrations are often insufficient to exert measurable physiological effects. This limitation has led to the incorporation of purified or concentrated bioactive compounds into food formulations [21]. However, such enrichment frequently alters the organoleptic properties of foods, making sensory quality a critical determinant of consumer acceptance and commercial success [22]. For example, the addition of functional ingredients can often result in bitter or astringent off-tastes [23].

Functional food science is an inherently interdisciplinary field focused on the development and application of bioactive compounds in food products [1,24]. These foods provide benefits beyond basic nutrition by exerting positive physiological effects on specific body functions, thereby contributing to disease prevention, improved quality of life, and reduced risk of chronic illnesses [2]. Beyond their biological activity, bioactive compounds can significantly influence taste, aroma, color, texture, and mouthfeel, thereby affecting overall product perception [25]. Consequently, the development of functional foods requires a careful balance between health-promoting potential and acceptable sensory characteristics, as unfavorable organoleptic attributes remain a major barriers to market uptake [26].

The concept of functional foods originated in Japan in the late 1980s, driven by increasing rates of non-communicable diseases among an aging population. This led to the introduction of the regulatory category “Foods for Specified Health Use” (FOSHU) in 1991 [27]. Since then, global interest in functional foods has expanded, and such products are now widely incorporated into daily diets.

Bioactive compounds comprise a diverse group of molecules derived from plant, animal, or microbial sources, many of which are classified as GRAS [4,5]. Among these, phytochemicals, such as polyphenols, carotenoids, and alkaloids, have attracted considerable attention due to their antioxidant, anti-inflammatory, antidiabetic, and cardioprotective properties [28,29]. However, these compounds are also strongly associated with sensory effects. For example, polyphenols are often associated with bitterness and astringency, largely because of their interactions with taste receptors and salivary proteins [30,31]. Carotenoids and anthocyanins play a major role in color development and stability, while omega-3 fatty acids are highly prone to oxidation, often resulting in undesirable off-flavors [32].

In recent years, food processing by-products have gained increasing attention as sustainable and cost-effective sources of bioactive compounds [33]. Seeds, peels, shells, bran, and pomace often contain higher concentrations of phenolic and dietary fibers than the edible portions of foods [8,34,35,36]. Examples include lycopene from tomato waste; phenolic compounds from apple pomace; polyphenols from grape by-products, and nutrients derived from avocado seeds and peels [9,35]. Growing research highlights the potential of these food processing residues as valuable sources of bioactive compounds for the development of functional foods [37]. Despite their functional potential, these materials present notable sensory challenges, including intense bitterness, astringency, dark coloration, and characteristic off-aromas [38]. As a result, technological interventions are often required to mitigate negative organoleptic impact while preserving bioactivity and safety.

Health and nutritional claims associated with functional foods must be supported by strong scientific evidence and are recognized only under specific, validated conditions. Their benefits are most effective when functional foods are consumed as part of a balanced dietary pattern, such as the Mediterranean diet [39].

Bioactive compounds in functional foods include prebiotics, probiotics, vitamins, phytochemicals, amino acids, peptides, omega-3 fatty acids, and antioxidants from diverse natural sources (

Table 1. Selected Bioactive Compounds in Foods and Beverages: Typical Concentration Ranges, Stability Considerations, and Main Analytical Methods. * Concentration ranges are indicative and depend on cultivar, processing, extraction method, and storage conditions.

Food/Beverage	Key Bioactive Compounds	Typical Concentration Ranges *	Stability Considerations	Main Analytical Methods	References
Coffee (Green & Roasted)	Caffeine, Chlorogenic acids, Trigonelline	Caffeine: 34–81 g/kg dry mass of extract; chlorogenic acids: 130–221 g/kg dry mass of lyophilized brews of coffee extracts (green beans)	Thermal degradation; oxidation	HPLC-DAD; HPLC-MS/MS	[43,44]
Tea	Epigallocatechin gallate, Catechin, Epicatechin, Galactatechin, Epigallocatechin, Galactoatechin gallate, Gallic acid	Gallic acid: 1.67–21.98 mg/g; epigallocatechins: 0.02–3.46 mg/g; catechin: 0.50–2.20 mg/g; epigallocatechin gallate: 13.34–14.03 mg/g; epicatechin: 0.95–8.86 mg/g; gallocatechin gallate: 0.49–1.21 mg/g; epicatechin gallate: 0.22–2.42 mg/g	Oxidation; heat sensitivity	HPLC-DAD; HPLC-MS/MS	[45,46]
Berries (e.g., Blueberry, Strawberry; Bilberry; Black currant)	Anthocyanins, Catechins, Epicatechin, Quercetin, Proanthocyanidins, Ellagitannins, Phenolic acids	Quercetin: 17–122 mg/kg; myricetin: 89–203 mg/kg; ellagitannins: 77.1–315.1 mg/100 g of fw	Sensitivity to oxygen; enzymatic activity; temperature; light exposure; pH	HPLC-DAD; HPLC-MS/MS	[47,48,49,50]
Pomegranate (Fruit, Juice, Peel)	Ellagitannins (punicalagins, granatins), Anthocyanins, Catechins, Epicatechin, Quercetin, Ellagic acid, Gallic acid	Total phenolic compounds: 1.03–3.39 mg GAE/g and 1562–2342 mg GAE/L (juice); Punicalagin A: 5.40–285 mg/L (juice), Punicalagin B: 25.9–884 mg/L (juice), Ellagic acid: 17.4–928 mg/L (juice), total anthocyanins: 2.1–168.5 mg/L (juice)	Light and oxygen sensitivity; thermal degradation; hydrolysis	HPLC; HPLC-DAD-ESI-MSn	[48,51,52,53,54]
Olive Oil	Oleic acid, Oleuropein, Polyphenols, Tocopherols	Polyphenols: 50–800 mg/L, Oleuropein: 2.04 mg/L, Total tocopherols: 238 mg/L	Oxidation; light exposure; thermal degradation	HPLC-DAD, HPLC-MS/MS	[48,55,56]
Ginger	Gingerols, Shogaols	Gingerols: 2.1–22 mg/g dry weight depending on the extraction method	Thermal conversion (gingerols to shogaols); oxidation	HPTLC, GC, GC/MS, HPLC, LC-MS	[48,57,58]

) [40,41]. Notable examples include resveratrol from grapes and red wine, antioxidant compounds from green tea, quercetin and ellagic acid from fruits and nuts, and anthocyanins from berries and grapes, which exhibit antioxidant, anti-inflammatory and chemoprotective effects. These compounds are valued for their antioxidant, anti-inflammatory, antidiabetic, anticancer, antiviral, and antitumor properties, helping to protect cells from damage caused by free radicals and reactive oxygen species [42].

Dietary fibers represent another important class of bioactive compounds widely used in functional foods. In addition to their well-recognized physiological benefits, fibers exert significant technological effects by modifying viscosity, texture, and mouthfeel, and are frequently employed as fat replacers or stabilizing agents [59,60,61]. Nevertheless, excessive fiber enrichment may negatively affect sensory attributes, leading to gritty textures, reduced flavor intensity, or impaired palatability, necessitating careful formulation and optimization [62].

A major challenge in using bioactive compounds is maintaining their stability during food processing, storage (e.g., temperature, oxygen, and light exposure), and digestion (e.g., pH, and enzyme activity). Technological innovations play a central role in addressing the sensory and stability limitations associated with these compounds. Encapsulation strategies, including micro- and nanoencapsulation, have been extensively investigated to protect bioactives from degradation, enhance their stability during processing and storage, and control their release in the gastrointestinal tract [63,64,65,66]. Importantly, encapsulation can also mask undesirable tastes and aromas, reduce astringency, and improve flavor balance in fortified foods [67].

Furthermore, due to their limited solubility and stability, novel approaches such as nanotechnology are being developed to enhance the solubility and bioavailability, and efficacy of bioactive compounds [15,68]. Nanoemulsions and lipid-based delivery systems have been shown to enhance the solubility, bioavailability, and mouthfeel of lipophilic bioactive compounds such as carotenoids and omega-3 fatty acids [69,70].

Food processing techniques, including fermentation, enzymatic treatments, and controlled thermal processing, may further modulate the sensory and functional properties of bioactive-enriched foods [71]. Fermentation, in particular, has been reported to reduce bitterness and astringency by modifying of phenolic profiles, while simultaneously improving flavor complexity and bioavailability [72,73]. However, processing conditions must be carefully optimized, as excessive heat, oxygen exposure, or light can degrade sensitive bioactive compounds and adversely affect both functionality and sensory quality [74].

Research on bioactive-enriched foods is rapidly expanding, as the effectiveness of functional and nutraceutical products largely depends on the stability, bioactivity, and bioavailability of these compounds [67]. Food processing can either enhance or reduce the concentration of functional components, making it essential to understand their behavior during processing and within a complex food matrix [75].

Despite the growing body of scientific evidence supporting the health benefits of bioactive compounds, most studies have focused on their extraction and characterization rather than on practical applications. Their incorporation into functional foods is often limited by poor stability, low bioavailability, and reduced sensory acceptance. Moreover, relatively few investigations address real food matrices, long-term sensory stability, consumer perception, or industrial scalability. These challenges, combined with strict regulatory frameworks governing health claims, further hinder the translation of scientific findings into commercially viable products [76].

Examples of successful applications include biscuits enriched with up to 10% white grape pomace, which improved both fiber and phenolic content [77]; encapsulated pomegranate peel extract used to stabilize hazelnut paste [78]; and functional chocolate milk enriched with omega-3 and omega-6 using soy phosphatidylcholine, which maintained stability and consumer acceptance [79].

3. Flavor Compounds in Functional Foods

Flavor compounds play a crucial role in the sensory appeal and consumer acceptance of functional foods. Volatile compounds such as esters, phenols, alcohols, terpenes, and aldehydes contribute primarily to aroma and are often formed through enzymatic breakdown of precursors or via secondary metabolic pathways [10,11]. In contrast, non-volatile compounds such as amino acids, fatty acids, and carbohydrates influence taste attributes, including sweetness, bitterness, and astringency [11].

The formation of flavor compounds involves complex biochemical and chemical processes that occur during food fermentation, processing, and storage. A deeper understanding of how these compounds are generated and regulated is essential for developing functional foods that offer both desirable sensory characteristics and health benefits.

Many aroma compounds in foods also exhibit significant bioactive properties, particularly in herbs, spices, vegetables, teas, and fermented products. In vegetables and medicinal or aromatic plants, polyphenols and volatile terpenes play a dual role by shaping characteristic sensory attributes (e.g., herbal, floral, and spicy notes) while simultaneously exerting antioxidant, anti-inflammatory, antimicrobial, and cardioprotective effects [80,81,82,83,84,85].

Volatile phenolic compounds derived from phenylalanine metabolism, including benzenoids and phenylpropanoids, constitute key odor-active constituents of fruits, herbs, and spices and have been reported to function as antioxidants and antimicrobial agents [80]. Similarly, sulfur-containing volatile compounds, such as isothiocyanates, thiols, and sulfides, are responsible for the distinctive aromas of Allium and Brassica vegetables, as well as mushrooms, and are implicated in plant defense mechanisms and human health protection, including anticarcinogenic and antimicrobial activities [86].

Essential oils rich in terpenes and terpenoids (e.g., thymol, carvacrol, and limonene) impart intense aromatic profiles and exhibit a broad spectrum of biological activities, including antimicrobial, antioxidant, anti-inflammatory, and, in some cases, anticancer effects. These properties support their application as natural preservatives in food systems [81,82,83,84].

Furthermore, microbial volatile compounds generated during fermentation contribute to characteristic sensory attributes and, in certain cases, are associated with probiotic functionality or other health-promoting effects, reinforcing the role of fermented products as functional foods [85].

3.1. Mechanisms of Flavor Compound Formation

3.1.1. Flavor Development in Non-Processed Foods

Plant-based foods are increasingly valued not only for their nutritional content but also for their richness in bioactive compounds. These bioactives, present in fruits, vegetables, grains, and other plant-derived sources, have been associated with a wide range of health benefits, including the prevention and management of chronic diseases.

Plant foods contain a diverse array of bioactive compounds, such as polyphenols (including flavonoids and phenolic acids), phytosterols, carotenoids, alkaloids, saponins, polysaccharides, and bioactive peptides [7,87,88]. In addition to insoluble and soluble dietary fiber, plant-based foods provide a wide spectrum of bioactives that may be crucial for disease prevention. Consequently, there is a growing trend toward incorporating plant-derived bioactives into functional food formulations to help prevent or manage non-communicable diseases [7,88,89].

Flavor compounds in plants are produced through complex biochemical pathways involving both primary and secondary metabolism. These pathways convert fatty acids, amino acids, and carbohydrates into a variety of volatile and nonvolatile compounds and are regulated by genetic, enzymatic, and environmental factors.

Many plant-derived flavor compounds originate from the metabolism of fatty acids, amino acids, and carbohydrates. Enzymatic reactions transform these precursors into volatile compounds such as alcohols, aldehydes, ketones, and ethers, as well as nitrogen- and sulfur-containing compounds [10,11]. Secondary metabolites, such as catechins, theanine, caffeine, and terpenes, are key contributors to the flavor of spices and tea. Their biosynthesis involves specific gene-encoded enzymes and is closely associated with plant taxonomy and organ development [11,13,90,91].

Gene-Encoded Enzymes Involved in Flavor Compound Synthesis

Terpene synthases

In kiwifruit, the enzyme AcTPS1 b, encoded by a terpene synthase gene cluster, produces 1,8-cineole, a major contributor to the fruit’s floral and eucalyptus-like aroma. Other genes within the same cluster encode enzymes responsible for the synthesis of sabinene, geraniol, and springer, each contributing distinct terpene compounds to the overall flavor profile [92].

In citrus fruits, the Cstps1 gene encodes a sesquiterpene synthase that converts farnesyl diphosphate into valencene, a key aroma compound. Expression of Cstps1 is developmentally regulated and responsive to ethylene, correlating with increased valencene levels during fruit ripening [93].

In Polygonum minus (generally known as ‘kesum’ in Malaysia), the PmSTPS1 and PmSTPS2 genes encode sesquiterpene synthases responsible for producing β-farnesene, α-farnesene, farnesol, and nerolidol, all of which are significant contributors to the plant’s aromatic profile [94].

Carotenoid cleavage dioxygenases

In tomato, the LeCCD1A and LeCCD1B genes encode carotenoid cleavage dioxygenases that generate flavor volatiles such as β-ionone, pseudoionone, and geranyl acetone by cleaving of carotenoid substrates. Silencing these genes leads to a significant reduction in these volatiles, confirming their role in flavor formation [95].

Enzymes involved in the synthesis of chiral flavor compounds

In tea flowers (Camellia sinensis), specific short-chain dehydrogenase/reductase (SDR) genes encode enzymes that convert acetophenone into the chiral flavor compounds (R)—and (S)—phenylethanol. The CsSPESs gene produces (S), phenylethanol, while the CsRPES gene produces (R), phenylethanol, both with high enantiomeric purity [96].

Glycosyltransferases involved in bitter flavonoid formation

The Cm1,2RhaT gene encodes a 1,2 rhamnosyltransferase, a key enzyme in the biosynthesis of bitter flavanone-7-O-neohesperidosides, which are responsible for the characteristic bitterness of certain citrus species [97].

In tea plants (Camellia sinensis), the CsUGT75L12 and CsUGT79B28 genes encode UDP-glycosyltransferases that sequentially glycosylate flavonoids, leading to the formation of bitter 7-O-neohesperidoside. These compounds contribute to both the bitterness and astringency of tea [98].

The expression of genes encoding these biosynthetic enzymes is a major determinant of plant flavor profiles. Advances in molecular biology have enabled the identification of many such genes, opening opportunities for metabolic engineering to enhance or modify flavor characteristics [10,13,90]. In tea plants, microRNAs (miRNAs) and plant hormones synergistically regulate the biosynthesis of key taste and aroma compounds by modulating gene expression networks [12,13,14,98].

Biosynthetic Pathways and Engineering

Many flavor compounds are derived from fatty acid, amino acid, and carbohydrate metabolic pathways, with genes encoding enzymes that catalyze key steps in their biosynthesis [10,90].

In fruits like mango, flavor compounds are synthesized via butanoate, phenylalanine, terpenoid, and fatty acid pathways. Metabolic flux through these pathways varies according to cultivar and developmental stage [11,98].

In grapes, terpenes (including monoterpenoids and sesquiterpenes) and norisoprenoids are major contributors to aroma. Terpene synthesis occurs early in berry development, often peaking before the onset of ripening (veraison). Norisoprenoids are derived from carotenoid cleavage, a process regulated by transcription factors such as VvWRKY70, which suppresses their formation by downregulating key biosynthetic genes [99,100,101].

Flavonols and anthocyanins, products of the flavonoid biosynthetic pathway, contribute to both flavor and color. Their accumulation is variety-dependent and influenced by environmental conditions and gene regulation [101,102]. Different grape varieties exhibit distinct volatile profiles, producing characteristic sensory notes such as fruity, floral, herbaceous, or muscat-like aromas. Specific compounds, such as linalool, α-pinene, and β-damascenone, are closely associated with these sensory attributes [102,103,104].

In addition to volatile compounds, grapes contain pools of non-volatile aroma precursors, including glycosides and amino acid conjugates. These precursors can be converted into volatile aroma compounds during fermentation, aging, or even oral consumption through enzymatic and chemical reactions [105,106].

Flavor compound formation is influenced by species, cultivar, climate, and agricultural practices. Postharvest handling, storage, and food processing techniques (e.g., fermentation and the Maillard reaction) also significantly affect the final flavor profile [11,13,107].

In functional foods, flavor compounds are often produced via microbial or plant biosynthetic pathways. Among the most significant are the Shikimate and Ehrlich pathways, which generate key aromatic compounds including 2-phenylethanol and various phenolic compounds that enhance both sensory properties and potential health benefits.

The Shikimate and Ehrlich Pathways

2-Phenylethanol, a rose-scented aromatic compound, is synthesized by various yeasts and bacteria through both the Shikimate and Ehrlich pathways. Microbial strains such as Kluyveromyces marxianus, Zygosaccharomyces rouxii, Starmerella bacillaris, and Yarrowia lipolytica have been engineered or identified for enhanced 2-phenylethanol production. Reported yields reached up to 1.94 g/L in engineered systems and 3.58 g/L under optimized fermentation conditions [108,109,110,111].

The Ehrlich pathway, which converts L-phenylalanine into 2-phenylethanol, is generally more efficient than the Shikimate pathway. This biosynthetic pathway comprises three sequential steps (reactions 1, 2, and 3, Figure 1, blue box). First, amino acids undergo deamination to yield the corresponding α-ketoacids, a reaction catalyzed by transaminases. Second, α-ketoacids are decarboxylated to their corresponding aldehydes by specific decarboxylases. Finally, alcohol dehydrogenases (specifically Adh1p-Adh6p and Sfa1p) reduce these aldehydes to form higher alcohols (Figure 1, blue box). When phenylalanine serves as the substrate, the aromatic compound 2-phenylethanol is formed (Figure 1, rose box) [111].

The Shikimate pathway (Figure 2) is crucial for the biosynthesis of the aromatic amino acids (phenylalanine, tyrosine, and tryptophan), which serve as precursors for a wide range of volatile phenols, phenylpropanoids, and benzenoid compounds. These metabolites are major contributors to the aroma and flavor of plant-based foods and are often stored as glycosides, from which aroma compounds are released during processing [112,113].

CRISPR-mediated multigene integration and metabolic engineering strategies have been applied to optimize the Shikimate and Ehrlich pathways in yeast, significantly enhancing the production of target flavor compounds such as 2-phenylethanol, mandelic acid, and vanillin [110,115,116]. Overexpression of key pathway genes, combined with the disruption of competing metabolic routes, can further increase production yields [110,115].

Flavor compound biosynthesis in functional foods is driven by both microbial fermentation (using yeasts and lactic acid bacteria) and plant metabolic pathways. During fermentation, lactic acid bacteria can produce flavor-active compounds, including aldehydes, esters, and alcohols, through the Ehrlich and Shikimate pathways [117]. In plants, the expression levels of Shikimate pathway genes correlate with the accumulation of phenolic compounds, thereby influencing fruit flavor and overall quality [113].

The ability to biosynthesize and regulate flavor compound production via these pathways provides valuable tools for developing functional foods with improved sensory properties and health benefits. Engineered microbes’ systems and optimized fermentation strategies offer a promising, sustainable, and scalable solution for the production of natural flavor compounds [108,109,110,111,115,116,117].

3.1.2. Flavor Development in Processed Foods

In processed foods, lipids are major contributors to flavor. Their degradation via autoxidation, photooxidation, and enzymatic oxidation results in the formation of volatile compounds such as aldehydes, alcohols, and ketones, which are central to flavor profiles. In particular, the oxidation of unsaturated fatty acids generates hydroperoxides that subsequently decompose into odor-active volatile compounds.

Lipids and lipid-derived oxidation products interact with other food components through Maillard and Strecker reactions during processing, cooking, and storage, thereby further diversifying the flavor profile [118,119,120]. These reactions between amino acids and reducing sugars at elevated temperatures produce a wide range of flavor active compounds, including branched-chain aldehydes and other volatiles. Such chemical pathways are highly relevant in both traditional and functional foods, as they play a critical role in shaping final sensory characteristics [107,118,119,121].

Microbial Contributions to Flavor

Microorganisms play a vital role in flavor development, especially in fermented functional foods. Through microbial metabolism, a wide range of aroma and flavor active compounds is produced, including organic acids, amino acids, and volatile compounds. Species such as Lactobacillus sp., Leuconostoc sp., and Pediococcus sp. are closely associated with the development of desirable flavor in fermented products [122,123,124].

Key volatile compounds generated through microbial activity, lipid oxidation, and Maillard reactions include aldehydes, alcohols, ketones, terpenoids, and phenolics. Among these, branched-chain aldehydes, are especially important in both fermented and heat-treated foods [107,120,121,125].

Microbial flavor formation is driven by coordinated carbohydrate, protein, and lipid metabolism. Fermentative carbohydrate pathways, primarily glycolysis followed by the production of lactic, acetic, propionic, and butanoic acids as well as ethanol, generate organic acids, alcohols, and esters that impart sour, fruity, and alcoholic notes [123,126,127,128]. Concurrently, proteolysis releases peptides and free amino acids, which are further catabolized into diverse volatile compounds, including aldehydes, acids, alcohols, and sulfur- and nitrogen-containing molecules. These compounds are central to flavor development in fermented dairy, meat, soy, and fish products [126,129].

Lipolysis and subsequent lipid oxidation generate free fatty acids and their derivatives, such as ketones, aldehydes, and lactones, which contribute critically to the characteristic sensory profiles of dairy and fish fermentations [126,130]. These processes are further refined by enzyme-mediated tailoring reactions, in which oxidoreductases, transferases, and hydrolases catalyze ester formation, protein modification (e.g., transglutaminase-mediated enhancement of umami), and the release of low-molecular-weight aroma compounds. Collectively, these reactions shape the final flavor profile of fermented foods [126,130,131].

Table 2. Representative microbial groups and their roles in food flavor development.

Food Type/System	Key Microbes Driving Flavor	Main Contributions	References
Vegetables (Paocai, Suancai, peppers)	Lactobacillus, Leuconostoc, Weissella, Companilactobacillus, Pichia	Organic acids, esters, sulfides, terpenes; sourness, fruity, complex aroma	[123,127,132,133]
Soy-based foods	Aspergillus, Bacillus, LAB, yeasts	Strong proteolysis, amino acid and lipid metabolism; umami, roasted, savory	[126,129]
Meat & fish (sour meat, fish, oysters)	Lactobacillus, Weissella, Staphylococcus, Psychrilyobacter, Fusobacterium, Saccharomyces	Alcohols, esters, nitrogen compounds, marine, and meaty notes	[134,135]
Cereals & alcoholic drinks (rice/wheat foods, baijiu, wine, huangjiu)	Saccharomyces, non-Saccharomyces yeasts, LAB, Bacillus, filamentous fungi	Ethanol, higher alcohols, esters, organic acids, heterocyclics	[127,128,136,137,138]

summarizes representative microorganisms and metabolic pathways that contribute to flavor development in foods.

Flavor is also influenced by “community succession” and microbial interactions (fungus–bacterium cooperation, quorum sensing), with early colonizers often setting pH and redox conditions that select later flavor-forming taxa [126,127,132,137]. Geography and the composition of the initial microbiota lead to region-specific flavor profiles (e.g., baijiu) [137].

In addition to volatile compounds, non-volatile constituents such as phenolics, saponins, peptides, and alkaloids contribute to taste and may offer health-promoting properties, including antioxidant and antimicrobial activities [107,125].

Microbial Succession and Biocatalysis

The succession of microbial communities and their metabolic activity significantly influence the accumulation of key volatile compounds, thereby helping to define the distinctive flavors of traditional fermented foods [122,126].

Microbial and enzymatic strategies are also used to produce non-volatile flavor compounds, such as umami and kokumi substances, which enhance depth and richness in flavor perception [139].

Biocatalysts (purified enzymes) and microbial fermentation are increasingly used for the sustainable controlled production of natural flavor compounds. Advances in enzyme engineering and bioprocess optimization have improved the specificity and efficiency of flavor compound synthesis, supporting the development of functional foods with tailored sensory profiles [122,124,140].

Challenges and Off-Flavor Mitigation

A persistent challenge in plant-based functional foods is the presence of off-flavors, such as “beany” notes. Strategies to reduce or eliminate these undesirable flavors include genome editing, antioxidant supplementation, enzyme treatments, and fermentation, all of which can modify, neutralize, or mask off-flavor compounds [107,124].

3.2. Technological Advances in Flavor Compound Production

3.2.1. Biocatalyst Encapsulation and Stabilization

Biocatalysts, including purified enzymes and engineered microorganisms, are increasingly used to sustainably and efficiently synthesize natural flavor compounds. These systems offer improved stereospecificity and environmental benefits, supporting the food industry’s shift toward greener and more sustainable production processes [122,139,140].

Encapsulation technologies using micro- and nanoscale carriers play a critical role in protecting volatile flavor compounds from degradation during food processing and storage. In particular, nanoencapsulation enhances the stability, bioavailability, and targeted delivery of flavor compounds, thereby broadening their application in food systems [141].

Among the most promising materials are sol–gel matrices, especially those formulated with organically modified silanes containing epoxy groups. These matrices effectively entrap enzymes such as lipases, significantly increasing both their operational and thermal stability. Lipases immobilized in these systems can retain up to 99% of their catalytic activity across multiple reaction cycles in flavor ester synthesis, enabling robust and scalable production [142].

Immobilization on biocompatible supports such as hydroxyapatite also provides excellent enzyme stabilization and retention of activity, even under harsh conditions, including elevated temperatures and exposure to organic solvents [143]. Additionally, mesoporous silica supports derived from biomass enhance enzyme selectivity and catalytic efficiency, thereby facilitating the mild, high-yield production of flavor esters [144].

Advanced systems, such as magnetic core–shell biocatalysts that combine covalent binding with sol–gel immobilization, offer improved operational stability and efficient enzyme recovery and reuse. These catalysts demonstrate high activity in the solventless synthesis of natural flavor esters across multiple production cycles [145].

The encapsulation of flavor compounds (e.g., limonene and α-terpineol) in oil-in-water nanoemulsions further enhances shelf life and maintains both physical and chemical stability, particularly under cool storage conditions. However, encapsulation stability tends to decrease at higher temperatures, highlighting the importance of optimized storage conditions [146]. Overall, nanoencapsulation provides superior encapsulation efficiency, stability, and controlled release compared to microencapsulation techniques. Novel technologies, including spray chilling, spray freeze drying, and electrospraying, further improve the encapsulation of heat-sensitive flavor compounds [147].

By enabling the production of natural, non-toxic, and environmentally friendly flavor compounds, immobilized and encapsulated biocatalysts support process optimization, scalability, and cost-effectiveness, key requirements for industrial application in the food sector [140,148,149]. Additionally, these technologies protect volatile and labile aroma compounds, enhancing their functionality and performance in complex food systems [147].

Nevertheless, several challenges remain, including optimizing process parameters (enzyme loading, support material, and reaction conditions) and gaining a deeper understanding of release mechanisms in real food matrices. Further research is needed to evaluate the effectiveness of encapsulated flavor compounds in both food products and gastrointestinal environments [147,148].

3.2.2. Flavor Recovery

Flavor recovery is a critical aspect of food flavor production, ensuring that valuable volatile aroma and taste compounds are efficiently captured, concentrated, and reused. This process not only enhances the sensory quality of food products but also promotes sustainability and cost-effectiveness in food manufacturing.

To recover and preserve volatile flavor compounds during liquid food processing, several advanced technologies are employed, including distillation, pervaporation, supercritical fluid extraction, and adsorption. These methods aim to minimize flavor losses while improving the final product quality [150]. Table 3 summarizes various techniques used in food flavor recovery.

Traditional methods, such as distillation and stripping, are commonly applied to recover volatile compounds from liquid food streams. Flash distillation, in particular, is used to isolate natural flavor compounds; however, it is often energy-intensive and may degrade thermally sensitive molecules [150,151].

Pervaporation utilizes selective membranes to separate and concentrate volatile flavor compounds from aqueous solutions. It is especially effective for recovering key aroma components from complex flavor systems, including apple essence, orange aroma, and black tea distillate. Pervaporation can achieve high concentration ratios for low-boiling-point volatiles, but process optimization (e.g., improved membrane sealing) is necessary to minimize flavor losses during scale-up operations [150,152].

Supercritical fluid extraction, particularly using carbon dioxide (CO₂), offers high selectivity and uses natural, non-toxic solvents, making it suitable for delicate matrices such as fruit juices. This method is particularly effective in preserving thermolabile flavor compounds.

Adsorption techniques, including solid-phase extraction (SPE), can be used alone or in combination with thermal processing to selectively recover and purify flavor compounds. These methods are especially valuable for recovering low-concentration or matrix-bound volatiles, which are often difficult to extract using conventional techniques [150,151,153].

Table 3. Techniques for Recovering Food Flavor.

Technique	Principle/Method	Key Advantages	Limitations/Considerations	References
Distillation/Stripping	Separation of volatiles by heating and condensation	Widely used, effective for many volatiles	Can be energy-intensive, may degrade sensitive flavors	[150,151,154]
Pervaporation	The selective membrane separates and concentrates volatiles from liquids	High selectivity, effective for low-boiling-point compounds	Flavor loss is possible due to leakage, and needs optimization	[150,151,152]
Supercritical Fluid Extraction	Uses supercritical CO2 or other fluids to extract flavors	High selectivity, uses natural solvents, suitable for sensitive matrices	Less commonly applied, needs further research	[150,151]
Adsorption (Solid-Phase Extraction, SPE)	Volatiles are adsorbed onto solid sorbents, then desorbed for analysis/recovery.	Can be tailored for specific compounds, good for complex matrices	Requires careful selection of sorbents and conditions	[150,151,153,155]
Solvent-Assisted Flavor Evaporation (SAFE)	Uses solvents to assist in evaporating and recovering volatiles	Effective for a wide range of volatiles	Fat content reduces the recovery of high-boiling volatiles	[155,156]
Salting-Out Re-distillation (SRD)	Uses salt to enhance the separation and recovery of odor-active compounds	High recovery rates improve flavor quality	Requires optimization of salt and process parameters	[154]
Headspace Techniques (SPME, HSSE, DTD)	Volatiles were collected from the headspace above samples using various sorbents.	Non-destructive, suitable for screening and analysis	May not recover all compound types equally	[156]
Flash Distillation	Rapid distillation under reduced pressure	Suitable for heat-sensitive flavors	High energy consumption, possible degradation	[151]

Table 3. Techniques for Recovering Food Flavor.

Technique	Principle/Method	Key Advantages	Limitations/Considerations	References
Distillation/Stripping	Separation of volatiles by heating and condensation	Widely used, effective for many volatiles	Can be energy-intensive, may degrade sensitive flavors	[150,151,154]
Pervaporation	The selective membrane separates and concentrates volatiles from liquids	High selectivity, effective for low-boiling-point compounds	Flavor loss is possible due to leakage, and needs optimization	[150,151,152]
Supercritical Fluid Extraction	Uses supercritical CO2 or other fluids to extract flavors	High selectivity, uses natural solvents, suitable for sensitive matrices	Less commonly applied, needs further research	[150,151]
Adsorption (Solid-Phase Extraction, SPE)	Volatiles are adsorbed onto solid sorbents, then desorbed for analysis/recovery.	Can be tailored for specific compounds, good for complex matrices	Requires careful selection of sorbents and conditions	[150,151,153,155]
Solvent-Assisted Flavor Evaporation (SAFE)	Uses solvents to assist in evaporating and recovering volatiles	Effective for a wide range of volatiles	Fat content reduces the recovery of high-boiling volatiles	[155,156]
Salting-Out Re-distillation (SRD)	Uses salt to enhance the separation and recovery of odor-active compounds	High recovery rates improve flavor quality	Requires optimization of salt and process parameters	[154]
Headspace Techniques (SPME, HSSE, DTD)	Volatiles were collected from the headspace above samples using various sorbents.	Non-destructive, suitable for screening and analysis	May not recover all compound types equally	[156]
Flash Distillation	Rapid distillation under reduced pressure	Suitable for heat-sensitive flavors	High energy consumption, possible degradation	[151]

The presence of fat in food matrices significantly affects the recovery of high-boiling-point volatile compounds during solvent-assisted flavor evaporation (SAFE). Elevated fat levels can hinder the release of these volatiles, whereas low fat content may reduce overall recovery yields. Maintaining a consistent fat concentration or diluting extracts can therefore improve recovery efficiency [155].

The effectiveness of flavor compound recovery also depends on the careful selection of extraction techniques and the optimization of process parameters. For example, the sequential application of different solid-phase extraction (SPE) phases can increase selectivity for specific flavor classes. This approach is particularly useful in complex food matrices, such as coffee, where it enhances the isolation of compounds like organosulfur volatiles [153].

From a sustainability perspective, sequential hydrolysis represents a promising strategy for recovering flavor compounds from food processing by-products, such as vanilla bagasse. This technique enables the extraction of high-value molecules such as vanillin, thereby supporting waste valorization and contributing to more sustainable production practices [157,158].

Combining biocatalytic steps (fermentation or enzymatic hydrolysis) with mild thermal processing can further facilitate the generation and recovery of natural flavors under nature-inspired conditions, aligning with the growing consumer demand for clean-label products [158,159].

In terms of innovation, Artificial Intelligence (AI) and big data analytics are increasingly applied to analyze flavor molecules, optimize formulations, and accelerate the discovery of novel flavor compounds. This digital approach is transforming the field, enabling faster, more efficient, and targeted flavor development [18].

3.3. Knowledge Gaps, Innovation Needs, Challenges, and Future Directions

Despite considerable progress, many enzymes and genes involved in flavor biosynthesis remain unidentified, limiting the potential of genetic engineering approaches to enhance flavor production [10]. Continued research is needed to optimize recovery, stabilization, and analytical methods, while also addressing regulatory, economic, and environmental challenges [124,140,141,160].

There is also a limited understanding of how flavor compounds are released from complex food matrices and perceived by consumers, especially in protein-rich and multifunctional foods [161]. Advancements in sensory evaluation techniques, biosensors, and neuroimaging tools are needed to better understand and optimize flavor perception and interactions in such products [18,162].

Further research is essential to refine the integration of biocatalytic, enzymatic, and thermal processing technologies for scalable, cost-effective, and sustainable production of flavor compounds [140,159,163].

The adoption of emerging technologies, particularly AI-driven analytics and advanced bioprocessing techniques, must be accompanied by comprehensive safety assessments and clear regulatory frameworks to ensure consumer protection and market acceptance [18,140].

Growing consumer demand for “clean-label”, natural, and minimally processed flavor solutions is driving innovation in biomediated production pathways [158,162,163]. Developing greener, more sustainable production methods remains a key priority for both the food industry and health-conscious consumers [122,140,163].

4. Advances in Food Biochemistry Technologies

The intersection of bioactive and flavor compounds in functional foods represents a rapidly evolving area of food science, driven by significant advancements in food biochemistry technologies. Recent research has highlighted how these compounds contribute not only to health benefits but also to the enhancement of sensory attributes in functional food products.

Food biochemistry technologies are transforming the stabilization, delivery, and controlled release of both bioactive and flavor compounds [164]. At the same time, consumer demand is shifting toward healthier, more aromatic, and flavorful products, motivating the food processing industry to develop innovative solutions [165].

Sustainability in the production of bioactive compounds has also become a major concern, for both consumers and the food industry, largely due to the environmental impact of waste generated during food processing [166,167].

4.1. Innovative Technologies Applied to Bioactive Compounds Extracted from Algae

In recent years, certain biological matrices, particularly algae and microalgae, have gained prominence as valuable sources of bioactive compounds for a wide range of applications [165]. Rich in nutritional constituents, including carotenoids, lipids, proteins, polysaccharides, dietary fiber, vitamins, and phenolic compounds, algae and microalgae hold significant potential as functional ingredients in the food sector [168].

Bioactive compounds derived from algae offer notable health benefits when incorporated into functional foods [169]. Consequently, several cutting-edge technologies have emerged to support the safer and effective applications of algae-derived bioactive compounds [170]. These innovations have the potential to transform both research and industrial applications of such compounds in food systems:

Precision fermentation employs genetically optimized microorganisms to produce specific bioactive compounds with enhanced efficiency and consistency. Encapsulation technologies protect sensitive bioactive compounds, improving their stability, bioavailability and long-term efficacy. In the food industry, encapsulation is particularly promising because it enables the controlled release of functional ingredients during specific phases of digestion [171,172].

Cold plasma, a non-thermal technology, can alter the composition of bioactive compounds without compromising their nutritional properties and, in some cases, may even enhance them [173,174]. It has also demonstrated effectiveness in removing undesirable contaminants, such as mycotoxins, thereby improving food safety and quality [175].

Similarly, pulsed electric field processing is a non-thermal technique that facilitates the efficient release of bioactive constituents from algae biomass by increasing cell membrane permeability. This enhances the separation of target compounds from the biological matrix and substantially enhancing their bioactivity and bioavailability [176,177].

High pressure processing is another non-thermal method that effectively preserves the nutritional and functional integrity of algae-derived bioactive compounds, ensuring that sensitive molecules remain active and beneficial after ingestion [178].

Finally, subcritical water extraction is a sustainable technology that operates at temperatures between 100 and 374 °C and pressures up to 22 MPa. This method preserves the nutritional and biological functionality of extracted compounds [179] while promoting the catalytic breakdown of complex macromolecules. These processes include the depolymerisation of polysaccharides into oligomers and monomers, and the fragmentation of proteins into peptides and amino acids, thereby improving digestibility and functional value [180].

The application of these advanced technologies to algae-derived nutrients and bioactive compounds, along with their associated health benefits, is summarized in

Table 4. Advanced technologies for algae-derived nutrients and bioactive compounds and their associated health benefits.

Algae Species	Bioactive Compound	Technology	Beneficial Effects	References
Arthrospira platensis	Protein, phenolic compounds, and volatile organic compounds	Precision fermentation by Lactobacillus helveticus (B-4526) and Kluyveromyces marxianus (Y-329)	Enriched essential amino acids, cardioprotective, anticarcinogenic, and antioxidant activity	[181]
Chlorella pyrenoidosa	Bioactive peptides	Encapsulation	Potentiates bioavailability in the intestinal tract	[182]
Nannochloropsis gaditana	Lipids (rich in ω-3 FA)	Encapsulation	Enhanced bioavailability	[183]
Saccharina jaonica	Polyphenols	Encapsulation	Enhanced bioavailability	[184]
Arthrospira platensis	Protein, phenolic compounds	Cold plasma	Potentiates antioxidant activity	[185]
Haematococcus pluvialis	Astaxanthin	Cold plasma	Potentiates antioxidant activity	[186]
Chlorella pyrenoidosa	Protein, polyphenol, pigments, and minerals	Pulsed electric field	Potentiates antioxidant activity	[120]
Saccharina japonica	Phenolic compounds	Subcritical water extraction	Potentiates antioxidant activity	[187]
Haematococcus pluvialis	Phenolic compounds	Subcritical water extraction	Potentiates antioxidant activity	[8]

.

These techniques hold considerable potential to enhance both the extraction efficiency and the biological activity of algae-derived compounds. To fully realize their benefits, further research is needed on pre- and post-treatment processes, including the optimization and standardization of protocols. Key parameters, such as treatment duration, application intensity, and environmental conditions, should be carefully optimized, particularly when applied to different algal species [177].

4.2. Emerging Techniques in Functional Food and Bioactive Compound Processing

4.2.1. Ultrasound

Emerging extraction methods, particularly ultrasound-assisted extraction, have significantly improved the efficiency of isolating bioactive compounds from various sources. This innovative technique aligns well with the principles of sustainable chemistry, as it is cost-effective, requires smaller volumes of solvents, and consumes less energy, while preserving the natural integrity of target compounds [17,188].

Ultrasound-assisted extraction operates by applying high-frequency sound waves that disrupt cellular structures, thereby facilitating faster solvent penetration and promoting the rapid release of bioactive compounds [189]. It is widely used to extract compounds such as polysaccharides (e.g., alginate and carrageenans), pigments (including β-carotene, fucoxanthin, and chlorophylls) and phenolic compounds [17].

Beyond conventional extraction, ultrasound technology also enables advanced applications, such as the production of multiphase colloidal nanoemulsions with particle sizes ranging from 10 to 100 nanometers. These nanoemulsions offer enhanced physicochemical stability, improved bioavailability, and targeted delivery of bioactive compounds within the human body [190].

However, as noted by Kumar et al. [189], some limitations remain, particularly regarding the extraction of bioactive compounds from fruit and vegetable by-products. A key challenge is the complete removal of chemical solvents used during processing. Further research is therefore needed to develop extraction systems that prevent direct contact between ultrasonic probes and plant materials, thereby improving both the safety and effectiveness of the technique.

4.2.2. Artificial Intelligence and Big Data

Advances in flavor science are increasingly enhancing the sensory profiles of foods through the integration of artificial intelligence (AI). AI-based flavor design platforms, such as TastePepAI, are being developed to create flavor peptides with targeted sensory attributes, including sweetness, saltiness, and umami, while ensuring both safety and efficacy [19]. To support this effort, the authors also introduced a toxicity prediction algorithm, SpepToxPred, which is integrated into the platform to ensure rigorous safety assessment of the obtained peptides. These bioactive peptides offer significant health benefits by reducing the need for sodium chloride, sucrose, and monosodium glutamate, while preserving desirable sensory qualities.

The exponential growth of data and advances in information technologies have led to substantial improvements in food ingredient and flavor databases [18]. These developments have transformed multiple aspects of the food industry, including supply chain optimization and food safety [191], as well as consumer perception, sustainability, and product innovation [192].

The application of big data analytics has also enabled the development of tools such as the nutritional assessment system proposed by Kalra et al. [193], which assists consumers in evaluating the nutritional quality of meals by calculating nutritional values directly from recipe analysis. Furthermore, the increasing adoption of AI and big data technologies across the food sector is expected to further enhance product sensory profiles and enable the creation of personalized flavors through predictive algorithms. These innovations are likely to play a decisive role in developing smarter, safer, and more sustainable food solutions that align with consumer expectations and public health objectives [192].

4.2.3. 3D Food Printing/Additive Manufacturing

Recent technological innovations are significantly transforming the development of functional foods by enabling more effective dispersion and enhanced stability of bioactive compounds and flavorings. One of the most promising advances in this field is 3D food printing, also known as Additive Manufacturing. This emerging technology represents a major innovation with substantial potential to impact the food sector. When applied to functional foods formulation, it enables the customization of sensory and nutritional characteristics meet individual consumer needs [194,195,196].

3D food printing operates similarly to conventional 3D printing for plastics and metals, constructing objects layer by layer from computer-aided design (CAD) models. However, instead of synthetic materials, edible ingredients are used as the printing substrates [196]. These materials can include a wide range of food matrices, such as vegetable or fruit purées, starch-based doughs or pasta, cheese, and meat products [189,197].

This technology enables the incorporation of bioactive compounds into foods specifically designed to meet individual nutritional requirements. It allows precise adjustment of key components, including proteins, dietary fibers, vitamins and minerals. In addition, 3D food printing can exclude allergenic substances, making the resulting products safer and more suitable for individuals with specific dietary restrictions [196,198].

Thus, additive manufacturing techniques such as 3D food printing provide precise control over the spatial distribution of bioactive compounds, thereby optimizing their stability and bioactivity in the final product.

4.2.4. Nanotechnology

The limitations of conventional techniques in preserving the functional properties of bioactive compounds have driven researchers to explore alternative technological approaches. Among these, nanotechnology has emerged as a promising strategy, as it can significantly enhance the bioaccessibility and bioavailability of bioactive compounds in the human diet [16]. A central advantage of this approach is that, when appropriately engineered, nanoparticles may exhibit low or even negligible toxicity to the human body. However, their safety depends heavily on factors such as material composition, particle size, dose, and exposure level; and therefore rigorous toxicological evaluation remains essential [199].

A wide range of micro- and nanoencapsulation techniques has been extensively described and applied in the food industry [200]. Owing to their extremely small size, bioactive compounds delivered by polymeric nanoparticles can penetrate biological barriers, including fine capillaries. This facilitates more efficient distribution and increased bioavailability in targeted tissues [201].

A notable example is lycopene, a naturally water-insoluble compound with limited intestinal absorption. When encapsulated in biodegradable nanoparticles, lycopene has demonstrated significantly improved uptake by intestinal cells, thereby enhancing its biological efficacy [16].

The application of nanotechnology in the food sector has also led to substantial improvements in sensory quality, facilitating industrial processing, and extending product shelf life. Most importantly, it has increased the functionality and performance of innovative food products [202].

Together, these technological advancements support the development of functional foods that effectively deliver health-promoting compounds, without compromising the sensory attributes valued by consumers.

5. Regulatory Framework for Novel Foods, Nanomaterials, and Health Claims

In the European Union (EU), foods that were not consumed to a significant extent prior to May 1997 are regulated under Regulation (EU) 2015/2283, which establishes a harmonized pre-market authorization procedure [203]. This regulation covers foods consisting of, isolated from, or produced using engineered nanomaterials, which are therefore subject to safety assessment prior to authorization. Scientific risk assessment of such applications is conducted by the European Food Safety Authority (EFSA), in accordance with guidance documents specifying the technical and scientific data requirements for novel foods and materials containing particles at the nanoscale [204,205].

The use of nutrition and health claims in the EU is regulated under Regulation (EC) No 1924/2006. Under this framework, health claims are evaluated by EFSA for scientific substantiation and are authorized only if the available evidence meets established criteria. Approved claims are subsequently included in the EU Register and are subject to specific conditions concerning wording, context of use, and target population. These requirements apply to both conventional and novel foods including those incorporating nanomaterials [206].

In the United States, the Food and Drug Administration (FDA) does not maintain a regulatory category directly equivalent to the EU concept of novel foods or engineered nanomaterials. Instead, products involving nanotechnology are regulated under the general framework for foods and food additives, with safety considerations assessed on a case-by-case basis [207]. Substances that are not generally recognized as safe (GRAS) may be subjected to pre-market review, regardless of the scale or structure of their constituent materials. Health claims in the US that relate to disease risk reduction require FDA authorization based on the available scientific evidence, whereas other claims, including structure/function claims, are subject to requirements concerning truthfulness and labelling [208,209].

Overall, while both the EU and US regulatory approaches share the objective of ensuring consumer protection and the integrity of scientific evaluation, while differing in their mechanisms: the EU employs a centralized pre-market assessment, particularly for novel foods and nanomaterials, whereas the US system relies on existing statutory provisions combined with guidance-driven, case-specific oversight [207,209].

6. Final Remarks

This review examines the convergence of nutrition, flavor science, and biotechnology in the development of functional foods, with the goal of understanding how flavor compounds can simultaneously provide desirable sensory properties and health-promoting benefits. The formation of these flavor compounds in plant-based and functional foods is driven by complex biochemical pathways, which are regulated by genetic, enzymatic, and environmental factors. Enzymes such as terpene synthases and glycosyltransferases play central roles in determining flavor profiles. Many aroma compounds, including terpenes, volatile phenols, sulfur-containing compounds, and polyphenols, also act as bioactive molecules, offering antioxidant, antimicrobial, and anti-inflammatory properties.

Advances in metabolic engineering, microbial fermentation, enzyme optimization, and processing techniques such as encapsulation and supercritical fluid extraction have enhanced the yield, stability, and sensory quality of these compounds. Future research should focus on integrated approaches that simultaneously address bioactivity, sensory quality, and technological feasibility. Such efforts should be supported by standardized sensory evaluation methods and in vivo validation, to bridge the gap between laboratory findings and the development of commercially viable functional foods.