Search Results (115)

‘Hainan Qingyou’ (Citrus maxima) Pomelo is one of the predominant local cultivars cultivated in Hainan Province, renowned for its high economic value and strong market competitiveness. However, during cultivation, it was observed that the fruit quality of ‘Hainan Qingyou’ grafted onto a ‘Sanhong’ interstock deteriorated, predominantly manifesting as vesicle granulation. This study was therefore conducted to investigate this phenomenon using ‘Sanhong’ Honey Pomelo as the interstock. Fruit quality indicators were measured, and pulp transcriptomic analysis was performed during the expansion and maturation stages. The results indicated that fruits grafted onto ‘Sanhong’ interstock (SHZ) exhibited increased peel thickness, yellower peel, reduced edible rate, higher pulp firmness, decreased total soluble solids (TSS), increased total acid content, and reduced total antioxidant capacity at maturity, all contributing to diminished fruit quality. Additionally, SHZ fruit accumulated higher lignin content in the pulp, leading to vesicle granulation, which severely compromised marketability. Transcriptomic analysis identified 42 structural genes involved in lignin biosynthesis in ‘Hainan Qingyou’ pulp, including 5 PAL, 2 C4H, 2 4CL, 6 CAD, 15 PER, 2 HCT, 1 C3′H, 1 CCoAOMT, 1 CCR, 1 COMT, 2 CSE, and 1 F5H genes. Most of these genes were highly expressed in SHZ fruit at maturity, with expression levels significantly higher than those in fruit grafted onto ‘Hainan Qingyou’ interstock (QYZ). The interstock also affected hormone signaling pathways. Weighted gene co-expression network analysis (WGCNA) identified transcription factors such as MYB, MIKC, ERF, and bZIP as key regulators involved in pulp lignin biosynthesis. This study provides insights into the effects of rootstocks on citrus fruit quality and offers valuable information for cultivar improvement in pomelo orchards. Full article

Citrus fruits and related processed products represent a major agricultural sector worldwide, contributing to food supply chains and to regional economies, particularly in Mediterranean and subtropical areas. Citrus processing generates significant amounts of post-processing waste, and their sustainable management is a critical challenge, driving growing scientific interest in exploring environmentally sustainable and profitable valorisation strategies. This study aimed at mapping the sustainability of post-processing citrus valorisation strategies documented in the scientific literature, through a scoping literature review based on the PRISMA-ScR model. Only peer-reviewed studies in English were selected from Scopus and Web of Science; in detail, 29 life cycle assessment studies (LCAs) focusing on the valorisation of citrus by-products have been analysed. Most of the studies were focused on essential oil extraction and energy production. Most of the biorefinery systems and valorisation aims proposed were found to be better than the business-as-usual solution. However, results are strongly influenced by the functional unit and allocation method. Economic allocation to the main product resulted in better environmental performances. The major environmental hotspot is the agrochemicals required for crop management. The analysis of LCAs facilitated the identification of valorisation strategies that deserve greater interest from the scientific community to propose sustainable bio-circular solutions in the agro-industrial and agricultural sectors. Full article

Dried orange pulp (Citrus sinensis) is known for its antioxidant properties. This study aimed to examine the effects of adding dried orange pulp (OP) to the layers’ diets on the concentration of selected elements in the egg. The present work was part of a bigger project aiming to investigate the effect of orange pulp in layers’ diets on the performance of birds and egg quality. There were three dietary treatments and 63 layers per treatment, with 189 layers in total. Cages were the experimental units, and seven cages were allocated per treatment (n = 7). The dietary treatments were (1) a control treatment (C) that involved a basal diet without orange pulp addition, (2) an OP treatment with the addition of 9% dried orange pulp, and (3) a hesperidin–naringin (EN) treatment with 0.767 g hesperidin and 0.002 g naringin added per kg of diet; these levels of hesperidin and naringin represent those present in dried orange pulp for the OP treatment. Birds were fed the diets for 30 days. The diets had similar energy and protein levels and contained the same vitamin and mineral premixes. The analyzed egg (yolk, albumen, shell) elemental profile consisted of As, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Sb, Se, Sr, V, and Zn and was determined via Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Dried orange pulp supplementation significantly altered the elemental profile. OP largely altered the element concentrations in albumen and egg yolk. Most notably, it decreased the concentrations of Co (p < 0.001), Fe (p < 0.001), Mn (p < 0.001), Ni (p = 0.046), and Se (p = 0.035) in egg yolk and those of Co (p = 0.011), Fe (p = 0.025), Cr (p = 0.049), Cu (p = 0.001), and Se (p = 0.014) in albumen. In addition, it decreased the concentrations of As (p = 0.025) and Ca (p = 0.025) in the eggshell. Principal component analysis was applied to the concentrations of the examined elements in all egg parts to explore the relationships between the elements and detect those capable of distinguishing samples, resulting in the apparent separation of yolk, albumen, and eggshell samples. Further analysis revealed that all samples were clustered into the three dietary treatments, resulting in 100% correct classification. The chelating and antioxidant capacities of flavonoids are intricate and rely on a variety of factors. OP supplementation modulated the deposition of specific elements in egg parts in comparison to those from layers fed a typical diet. Thus, this study indicated that eggs with specialized elemental profiles could be created. Full article

Wendan pomelo (Citrus maxima), valued for its unique quality and high nutritional value, is susceptible to postharvest decay caused by mechanical damage and fungal infection. This study developed a bio-based preservation strategy by incorporating Bacillus subtilis (B. subtilis) into a sodium alginate (SA)-based coating. An antagonistic B. subtilis strain, isolated from the pomelo growth environment, demonstrated effective inhibition against the pathogenic fungi P. digitatum and P. italicum. The B. subtilis/SA (2.0%) coating maintained high bacterial viability without adversely affecting the viscosity, gas barrier properties, or mechanical strength of the film. The application of the B. subtilis/SA coating significantly delayed fruit appearance deterioration, pulp softening, and decay in pomelo. Furthermore, the treatment enhanced flavonoid accumulation and increased the activity of antioxidant enzymes, thereby maintaining quality and extending storage life to 90 d. This study provides an effective bio-preservation strategy for the postharvest management of pomelo. Full article

Agro-industrial residues can improve the fermentation quality of tropical forage grass silages when used as additives, but a systematic synthesis of their effectiveness is limited. This integrative review aimed to identify the main residues used as additives in silages and assess their effects on the fermentation process. Following the PVO (population, variable of interest, and outcome) protocol, searches were conducted in the Wiley Online Library, Web of Science, and SCOPUS databases, with no restrictions on language, time, or region. The guiding question was: “What are the main agro-industrial residues used as additives in the ensiling of tropical forage grasses?” Of the 1414 documents initially retrieved, 138 were selected after screening titles, abstracts, and keywords. After removing duplicates and full-text evaluation, 58 studies met the inclusion criteria. Brazil led in the number of studies (89.66%). Elephant grass (Pennisetum purpureum Schum.) was the most studied forage (34.21%). Citrus pulp (13.79%) and coffee husk (12.07%) were the most evaluated residues. The addition of residues promoted a reduction in pH (66.07%), ammonia nitrogen (71.74%), buffer capacity (57.14%), and the concentrations of acetic (52.17%), propionic (52.63%), and butyric (55.00%) acids. Lactic acid content increased in 32.76% of studies; gas and effluent losses decreased in 69.57% and 86.36% of cases, respectively. Citrus pulp and coffee husk are the most used residues, enhancing fermentation quality. It is concluded that the use of agro-industrial residues in the ensiling of tropical forage grasses has the potential to improve fermentation quality. Full article

The blood orange arose from the insertion of a retrotransposon adjacent to the Ruby gene, an MYB-type transcriptional activator of anthocyanin production, as reported previously. However, the intricate process of anthocyanin regulation among different varieties of blood orange remains incompletely understood. In this study, mRNA levels of the transcription factors Ruby and TT8 were found to be upregulated in the juice vesicle tissues of a variety with higher concentrations of anthocyanins in the pulp compared with another variety with a lower anthocyanin content. In contrast, comparative analysis of the two varieties using two-dimensional electrophoresis and mass spectrometry did not identify differentially expressed proteins related to anthocyanin biosynthesis in the juice vesicle tissues. Furthermore, higher anthocyanin contents were observed in various tissues of transgenic Arabidopsis thaliana overexpressing the Ruby gene from blood orange compared with the wildtype plant. Moreover, the long terminal repeat (LTR) region of a retrotransposon inserted upstream of the Ruby locus exhibited the ability to drive reporter expression through histochemical assay in a transgenic seedling. Thus, a PCR-based molecular marker was developed, targeting the upstream sequence of the Ruby locus to identify Citrus hybrids with the unique trait of red-fleshed fruit. Intriguingly, bisulfite sequencing revealed differentially methylated regions within a Gag-Pol polyprotein-encoding sequence of a retrotransposon adjacent to Ruby locus when comparing two varieties with different anthocyanin contents. A higher average level of methylation status was observed in the fruit with a lower anthocyanin content. In conclusion, methylation modifications at specific upstream positions on the Ruby locus may influence anthocyanin production in blood oranges. Full article

Orange allergy is estimated to account for up to 3–4% of food allergies. Major allergens identified in orange (Citrus sinensis) include Cit s 1 (germin-like protein) and Cit s 2 (profilin), while Cit s 3 (non-specific lipid transfer protein, nsLTP) and Cit s 7 (gibberellin-regulated protein) have also been described. The objective of this study was to investigate the presence and IgE-binding capacity of germin-like proteins in citrus fruits other than oranges. We describe five patients with immediate allergic reactions after orange ingestion. All patients underwent skin prick tests (SPT) to aeroallergens and common food allergens, prick-by-prick testing with orange, lemon, and mandarin (pulp, peel, seeds), total IgE, specific IgE (sIgE), anaphylaxis scoring (oFASS), and the Food Allergy Quality of Life Questionnaire (FAQLQ-AF). Protein extracts from peel and pulp of orange, lemon, and mandarin were analyzed by Bradford assay, SDS-PAGE, and IgE immunoblotting using patient sera. Selected bands were identified by peptide mass fingerprinting. A 23 kDa band was recognized by all five patients in orange (pulp and peel), lemon (peel), and mandarin (peel). This band was consistent with Cit s 1, a germin-like protein already annotated in the IUIS allergen database for orange but not for lemon or mandarin. Peptide fingerprinting confirmed the germin-like identity of the 23 kDa bands in all three citrus species. Germin-like proteins of approximately 23 kDa were identified as IgE-binding components in peel extracts of orange, lemon, and mandarin, and in orange pulp. These findings suggest a potential shared allergen across citrus species that may contribute to allergic reactions independent of LTP sensitization. Full article

Pummelo (Citrus maxima) is an ancestral species that has given rise to several major citrus varieties, such as sweet orange (C. x aurantium var. sinensis) and grapefruit (C. x aurantium var. paradisi). This species is also cultivated and its fruit consumed, particularly in Asia. Over the course of evolution, the allogamous reproduction of pummelos and the absence of asexual multiplication have contributed to its diversification. To assess its phenotypic diversity and the chemical composition of leaf and peel essential oils, genetic analysis using DNA markers is an essential prerequisite to ensure the identity and if varieties belong to this species. Fifty-eight accessions classified as grapefruits or pummelos were analyzed using 42 SSRs, 4 Indels, and 36 SNP markers. Based on the allelic composition of these markers, 20 cultivars were detected belonging to pummelos, 18 cultivars to grapefruits, and 11 were interspecific hybrids. The grapefruit inter-cultivar SSR diversity is null. The genetic origin of five interspecific hybrids is elucidated. The level of phenotypic diversity and of essential oil composition corroborate the modes of diversification, with high levels for those resulting from crosses and very low levels for the group of grapefruit mutants. Only the characteristics of breeding selection (pulp color, acidity and aspermia) are variable in grapefruits. In the composition of leaf essential oils (LEOs), nine profiles were detected in grapefruits based on variations in six compounds (neral, geranial, β-phellandrene, γ-terpinene, (E)-β-ocimene, and β-pinene). The seven interspecific hybrids involving pummelo as one parent show particular LEO profiles but without specific compounds, with the exception of p-cymenene which is present only in Wheeny. The diversity of peel essential oils in pummelos is lower, but variations in γ-terpinene, β-pinene, limonene, and myrcene make it possible to define seven profiles. With genetic verification the chemical and phenotypic diversity of the two species, pummelo and grapefruit, revealed in this study can be used as a reference for behavior in a specific environment. Full article

Domestic food waste and agro-industrial by-products (AIBPs) occurring throughout the food chain, including production, processing, and storage, have become a global sustainability concern. Interestingly, this waste and these by-products contain a significant amount of commercially vital bioactive compounds, including polyphenols and carotenoids. Remarkably, discarded by-products such as fruit and vegetable peels contain more bioactive compounds than edible pulp. Thus, valorizing this waste and these by-products for commercially vital bioactive products can solve their disposal problems and help alleviate climate change crises. Additionally, it can generate surplus revenue, significantly improving food production and processing economics. Interestingly, several bioactive extracts derived from citrus peel, carrot pomace, olive leaf, and grape seed are commercially available, highlighting the importance of agro-food waste and by-product valorization. Considering this background information, this review aims to provide holistic information on major AIBPs; recovery methods of bioactive compounds focusing on polyphenols, carotenoids, oligosaccharides, and pectin; microencapsulation of isolated bioactive for enhanced physical, chemical, and biological properties; and their commercial application. In addition, green extraction methods are discussed, which have several advantages over conventional extraction. The concept of the circular bio-economy approach, challenges in waste valorization, and future perspective are also discussed. Full article

Among the numerous diseases that affect papaya (Carica papaya L.) cultivation, anthracnose, caused by a complex of fungi from the genus Colletotrichum spp., stands out, primarily due to its damage to the commercial part of the papaya, the fruit, specifically the pulp. Although chemical control with synthetic molecules is the most commonly used method to combat anthracnose, it is not the most appropriate solution. The indiscriminate use of synthetic chemical products results in numerous harmful effects on the environment, the health of farmers, and the final consumers. Given these circumstances, the objective of this study was to analyze the efficacy of essential oils (EOs) from Citrus aurantium var. dulcis L., known as sweet orange, Citrus limon (L.), known as Sicilian lemon, and the major compound present in these oils, limonene, against the pathogens Colletotrichum okinawense, which cause anthracnose in papaya fruits. The percentage inhibition of mycelial growth was evaluated on the seventh day, with estimates of 50% and 90% inhibition, to compare the inhibitory effect among the fungal isolates. Chromatographic analysis revealed that sweet orange EO contains myrcene and limonene. Sicilian lemon essential oil includes myrcene, limonene, α- and β-pinene, and γ-terpinene. Both EOs and limonene exhibited activity against C. okinawense. The 50 µL/mL concentration was the most effective in inhibiting growth. The EOs and limonene showed similar IC₅₀ values, with limonene at 48 µL/mL, Sicilian lemon EO at 51 µL/mL, and sweet orange EO at 57 µL/mL. Full article

In normal conditions, neuroinflammation induces microglia and astrocyte activation to maintain brain homeostasis. However, excessive or prolonged neuroinflammation can inflict harmful damage on brain tissue. Numerous factors can trigger chronic neuroinflammation, ultimately leading to neurodegeneration. In this context, considering the pressing need for novel, natural approaches to mitigate neuroinflammatory damage, attention has turned to unconventional sources such as agricultural by-products. Citrus fruits are widely consumed globally, producing substantial waste, including peels, seeds, and pulp. Traditionally regarded as agricultural waste, these by-products are now recognized as valuable reservoirs of bioactive compounds, including flavonoids, carotenoids, terpenoids, and limonoids. Among these, citrus polyphenols—particularly flavanones like hesperidin, naringenin, and eriocitrin—have emerged as potent modulators of neuroinflammatory pathways through their multifaceted interactions with cellular antioxidant systems, pro-inflammatory signaling cascades, neurovascular integrity, and gut–brain axis dynamics. This review aims to characterize the key molecules present in citrus waste and synthesizes preclinical and clinical evidence to elucidate the biochemical mechanisms underlying neuroinflammation in neurodegenerative disorders. Full article

Citrus cultivars are propagated asexually through methods such as layering, cutting, and grafting. Grafting plays a critical role in regulating citrus fruit quality by optimizing stock–scion combinations. This study evaluated the grafting compatibility of two interstocks with Cocktail grapefruits (Citrus paradisi Macf. cv. Cocktail) by analyzing physiological and volatile traits of the fruits. We used Changshanhuyou (Citrus paradisi cv. Changshanhuyou) and Ponkan (Citrus reticulata Blanco cv. Ponkan), which are traditional citrus varieties in Quzhou, Zhejiang Province, as interstocks. Our results showed that the grapefruit fruits grafted onto Changshanhuyou exhibited higher total soluble solids (12.3 °Brix) and a brighter, more uniform peel color. The acidity of fruits grafted onto Changshanhuyou was lower than that of fruits grafted onto Ponkan and similar to the fruits from the control group that were grafted directly onto trifoliate orange. In terms of volatile organic compounds (VOCs), 974 and 577 unique VOCs were identified in the peel and pulp, respectively. In the peel, 34 (26 upregulated and 8 downregulated) and 14 (13 upregulated and 1 downregulated) differentially accumulated VOCs were identified when comparing the trifoliate orange group with Changshanhuyou and Ponkan groups, respectively. The pulp exhibited greater VOC diversity, with 272 (24 upregulated and 248 downregulated) and 199 (4 upregulated and 195 downregulated) differentially accumulated VOCs detected for the same comparisons. In conclusion, compared with direct grafting onto trifoliate orange or on Ponkan as an interstock, grafting onto Changshanhuyou resulted in better fruit quality and distinct differences in flesh flavor. These findings suggest that Changshanhuyou is a more suitable interstock for Cocktail grapefruit (Citrus paradisi Macf. cv. Cocktail) cultivation. Full article

Citrus is a globally consumed fruit with great popularity, yet systematic analyses of primary metabolites across major varieties remain scarce, with phenolic acids as an auxiliary focus due to their flavor relevance. In this study, the primary metabolites and phenolic acids of five citrus varieties were analyzed via liquid chromatography‒tandem mass spectrometry (LC–MS/MS). The analysis revealed that five different citrus varieties contained 342 primary metabolites and 77 phenolic acids. The PCA clearly distinguished the metabolites of various citrus varieties. Compared with the pomelo group, the lemon group presented the most differentially abundant metabolites, whereas the kumquat and navel orange groups presented the fewest. An examination of metabolic pathways with notable disparities revealed that phenylpropanoid biosynthesis and the biosynthesis of amino acids significantly varied between varieties. This study elucidates primary metabolic networks underlying citrus flavor diversification, with phenolic acids providing secondary modulation insights. Moreover, this study provides a theoretical foundation for enhancing the flavor of citrus fruits. Full article

During plant development or interactions with pathogens, modifications of the plant cell wall occur. Among the enzymes involved, pectinases, particularly polygalacturonases (PGases), play a crucial role in the controlled hydrolysis of cell wall polysaccharides, leading to the formation of oligogalacturonides (OGs). These pectin-derived fragments act as key elicitors of plant defense responses, stimulating innate immunity and enhancing resistance to pathogens by modulating the expression of genes involved in immune responses and inducing the production of defense compounds. OGs are of particular interest for plant protection as a natural alternative to conventional phytosanitary products as they can be obtained through chemical, thermal, or enzymatic degradation of plant biomass. In a sustainable approach, agricultural by-products rich in pectin, such as citrus peels, apple pomace, or sugar beet pulp, offer an eco-friendly and cost-effective alternative for OG production. Thus, the current review aims to (i) update the state of the art about the different methods used to produce OGs, (ii) explore the potential of OGs as bio-based biocontrol molecules, and (iii) examine the relevance of new pectin sources for OG production. Full article

Phytochemicals, such as flavonoids, are bioactive compounds produced by plants, including citrus fruits, that exhibit antioxidant effects on mammalian cells and tissues. Polymethoxyflavones (PMFs) are a family of flavonoids found in the pulp and peel of citrus fruits, and have been reported to have potent antioxidant activity implicated in the prevention of human diseases. Several studies have shown that PMFs have a protective effect on bone resorption in mouse models of diseases, including osteoporosis, rheumatoid arthritis, and periodontal disease. PMFs significantly suppressed the differentiation of osteoclasts (bone resorptive cells) through indirect and direct mechanisms. The indirect effect of PMFs is the suppression of inflammatory mediator production, such as prostaglandin E2 (PGE2), and the reduction of osteoclastic inducers, such as the receptor activator of NF-κB ligand (RANKL), in osteoblasts (bone-forming cells). The direct effect of PMF suppresses osteoclast differentiation and function by inhibiting the NF-κB signaling pathway. In silico molecular docking studies indicated that PMFs target the ATP-binding pocket of IKKβ and inhibit the NF-κB signaling pathway. These findings suggest that PMFs protect against bone destruction by interfering with the NF-κB pathway in osteoblasts and osteoclasts. In this review, we summarize the latest findings regarding the effects of PMFs on various bone resorption-related diseases in mouse models. Full article