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Special Issue "Colorants Changes during Food Treatment and Processing"

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Applied Chemistry".

Deadline for manuscript submissions: closed (31 August 2021) | Viewed by 9959

Special Issue Editors

Dr. Emilia Janiszewska-Turak
E-Mail Website
Guest Editor
Institute of Food Sciences Department of Food Engineering and Process Management, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159, Warszawa, Poland
Interests: encapsulation; fruit and vegetable juices; spray drying; micronization
Special Issues, Collections and Topics in MDPI journals
Dr. Malgorzata Nowacka
E-Mail Website
Guest Editor
Department of Food Engineering and Process Management, Institute of Food Sciences, Warsaw University of Life Sciences – SGGW Warsaw, 02-787, Poland
Interests: non-thermal technologies as ultrasound and pulsed electric field; osmotic dehydration; drying; design new products; sustainable methods of food production
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The color of food is one of the attributes that consumers mostly pay attention to when choosing food products. Colorants, both those present in raw materials as well as those added during technological processes, are responsible for creating food color. Currently, increasing attention is being paid to colorants obtained from natural sources, such as fruit and vegetables. However, during technological processes, changes in natural colorants and degradation can occur. In particular, thermal processes such as drying, baking, boiling, frying, blanching, microwave processing, etc., cause color changes. However, innovative and non-thermal food processing technologies have become increasingly popular in recent years. They are used not only to preserve bioactive compounds in the treated material but also to maintain the color, taste, and smell of food products. These innovative and emerging technologies include pulsed electric field, ultrasound, high-pressure treatment, vacuum impregnation, cold plasma treatment, ozone application, ultraviolet treatment, pulsed light processing, and osmotic dehydration.

For this Special Issue, we invite researchers to contribute original research and review articles that analyze and describe changes in natural colorants during treatment and technological processing. Descriptions accompanied by a possible explanation of the mechanism which occurs during food processing are welcome.

Potential topics include, but are not limited to the following:

  • Changes in colorants of raw food materials during and/or after thermal processing
  • Effect of non-thermal processes on the food color and compounds responsible for the color
  • Changes in colorants added to the food matrices and subject to processing

Dr. Emilia Janiszewska-Turak
Dr. Malgorzata Nowacka
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2300 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • color
  • coloring compounds
  • food processes
  • thermal processes
  • non-thermal processes

Published Papers (11 papers)

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Research

Article
Innovative Freeze-Dried Snacks with Sodium Alginate and Fruit Pomace (Only Apple or Only Chokeberry) Obtained within the Framework of Sustainable Production
Molecules 2022, 27(10), 3095; https://doi.org/10.3390/molecules27103095 - 11 May 2022
Viewed by 219
Abstract
The aim of the work has been to develop freeze-dried fruit snacks in the form of bars with the use of by-products derived from fruit processing. In effect 14 product designs of fruit gels based on: apple pulp, apple juice, water, sodium alginate [...] Read more.
The aim of the work has been to develop freeze-dried fruit snacks in the form of bars with the use of by-products derived from fruit processing. In effect 14 product designs of fruit gels based on: apple pulp, apple juice, water, sodium alginate and only apple or only chokeberry pomace were prepared. The snacks were freeze-dried. The dry matter content, water activity, structure, colour, mechanical properties, as well as organoleptic evaluation were determined. Freeze-dried bares were obtained according to sustainability production which in this case was relied on application of fruit pomace. The freeze-drying process ensures the microbiological safety of the product without the need to use chemical preservatives. Freeze-dried samples obtained low water activity in the range of 0.099–0.159. The increase in pomace concentration (3–9%) boosted the dry matter content to above 98%, and decreased the brightness of the freeze-dried bars about 6 to 10 units. Mechanical properties varied depending on the product design. With the increase in the amount of pomace, the shear force increased at 23% to 41%. Based on the results, the best variant, that has the most delicate structure and the best organoleptic properties, has proven to contain 1% sodium alginate and 2% pomace. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
Influence of Fermentation Beetroot Juice Process on the Physico-Chemical Properties of Spray Dried Powder
Molecules 2022, 27(3), 1008; https://doi.org/10.3390/molecules27031008 - 02 Feb 2022
Viewed by 624
Abstract
Picking vegetables is, along with salting and drying, one of the oldest ways to preserve food in the world. This is the process of decomposition of simple sugars into lactic acid with the participation of lactic bacteria. The aim of the study was [...] Read more.
Picking vegetables is, along with salting and drying, one of the oldest ways to preserve food in the world. This is the process of decomposition of simple sugars into lactic acid with the participation of lactic bacteria. The aim of the study was to obtain powders from fermented red beet juice with the highest possible amount of lactic acid bacteria (LAB) and active ingredients. For the analysis, juices were squeezed from the vegetables and two types of fermentation were used: a spontaneous fermentation and a dedicated one. After inoculation, samples were taken for analysis on a daily basis. Extract, pH, total acidity, pigments, and color were measured. In addition, microbiological tests were also carried out. The juices from the fifth day of fermentation was also spray dried, to obtain fermented beetroot powder. Juices from 3–5th day were characterized by a high content of LAB and betanin, had also a low pH, which proves that the lactic fermentation is working properly. The exception was the juice from spontaneous fermentation. According to the observations, the fermentation process did not run properly, and further analysis is needed. The powders were stable; however, results obtained from the pigment content and the LAB content are not satisfactory and require further analysis. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
Effect of Calcium Compound Type and Dosage on the Properties of Acid Rennet Goat’s Milk Gels
Molecules 2021, 26(18), 5563; https://doi.org/10.3390/molecules26185563 - 13 Sep 2021
Cited by 1 | Viewed by 676
Abstract
The aim of this study was to determine the effect of adding calcium compounds to processed goat’s milk, and on the properties of acid rennet goat’s milk gels, which are a middle product obtained in the manufacture of acid rennet cheese. The properties [...] Read more.
The aim of this study was to determine the effect of adding calcium compounds to processed goat’s milk, and on the properties of acid rennet goat’s milk gels, which are a middle product obtained in the manufacture of acid rennet cheese. The properties of the gels directly affect the quality of acid rennet cheeses. The analysis of raw goat’s milk was carried out, then acid rennet gels were produced with the addition of six different calcium compounds (chloride, citrate, bisglycinate, gluconate, lactate, and carbonate). The dynamics of milk fermentation were performed by monitoring the pH value of milk during acidification. The pH, syneresis, color, and texture profile were determined in the formulated acid rennet gels. An organoleptic evaluation was also performed. The study demonstrated that, not only calcium chloride, but also calcium citrate, gluconate, lactate, bisglycinate, and calcium carbonate could be used in the production of goat’s milk acid rennet gels, or the middle product in the manufacture of acid rennet curd cheese from goat’s milk. Notably, the addition of citrate, bisglycinate, and calcium carbonate in doses of 20 mg Ca 100 g−1 most effectively reduced syneresis compared to the control sample by 4.76% (citrate), 7.85% (bisglycinate), and 10.28% (carbonate). The hardness of the control gels ranged from 2.35 N to 2.99 N. The addition of chloride, citrate, gluconate, lactate, and calcium carbonate to the milk improved the acid rennet gel’s hardness. The addition of 20 mg Ca 100 g−1 as gluconate increased the hardness the most (3.61 N). When increasing the calcium dosage in the form of all compounds, there was a tendency to increase the gel’s springiness. The addition of chloride, citrate, and bisglycinate to milk did not result in a darkening of the gel’s color. The addition of calcium compounds mostly reduced the intensity of goatish taste and odor. Calcium gluconate, in particular, reduced the goatish taste the most, a taste which is not always acceptable by the consumers. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
The Influence of Different Pretreatment Methods on Color and Pigment Change in Beetroot Products
Molecules 2021, 26(12), 3683; https://doi.org/10.3390/molecules26123683 - 16 Jun 2021
Cited by 3 | Viewed by 1092
Abstract
Vegetable processing pomace contains valuable substances such as natural colors that can be reused as functional ingredients. Due to a large amount of water, they are an unstable material. The aim of our research was to assess how the pretreatment method (thermal or [...] Read more.
Vegetable processing pomace contains valuable substances such as natural colors that can be reused as functional ingredients. Due to a large amount of water, they are an unstable material. The aim of our research was to assess how the pretreatment method (thermal or nonthermal) affects the properties of powders obtained from beet juice and pomace after the freeze-drying process. The raw material was steamed or sonicated for 10 or 15 min, and then squeezed into juice and pomace. Both squeezed products were freeze-dried. The content of dry substance; L*, a*, and b* color parameters; and the content of betalain pigments were analyzed. Pretreatments increased the proportion of red and yellow in the juices. Steam and ultrasound caused a significant reduction in parameter b* in the dried pomace. A significant increase in betanin in lyophilizates was observed after pretreatment with ultrasound and steam for 15 min. As a result of all experiments, dried juices and pomaces can also be used as a colorant source. However, there is higher potential with pomaces due to their additional internal substances as well as better storage properties. After a few hours, juice was sticky and not ready to use. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
Characterization of Food Packaging Films with Blackcurrant Fruit Waste as a Source of Antioxidant and Color Sensing Intelligent Material
Molecules 2021, 26(9), 2569; https://doi.org/10.3390/molecules26092569 - 28 Apr 2021
Cited by 4 | Viewed by 892
Abstract
Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor [...] Read more.
Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by DSC, were reduced by 18 °C for chitosan-based samples and of 32 °C lower for the pectin-based samples with blackcurrant powder, indicating a disturbance in polymer stability. The antioxidant activity of active films was increased up to 30-fold. Lightness and redness of dry films significantly changed depending on the polymer type. Significant color changes, especially in chitosan film formulations, were observed after exposure to different pH buffers. This effect is further explored in formulations that were used as color change indicators for intelligent biopackaging. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
Polyphenols, L-Ascorbic Acid, and Antioxidant Activity in Wines from Rose Fruits (Rosa rugosa)
Molecules 2021, 26(9), 2561; https://doi.org/10.3390/molecules26092561 - 28 Apr 2021
Cited by 3 | Viewed by 787
Abstract
The aim of the present study was to determine the influence of the winemaking process on the antioxidant potential and content of phenolic compounds and L-ascorbic acid in wines from the fruits of Rosa rugosa. The results obtained in this study clearly [...] Read more.
The aim of the present study was to determine the influence of the winemaking process on the antioxidant potential and content of phenolic compounds and L-ascorbic acid in wines from the fruits of Rosa rugosa. The results obtained in this study clearly indicate that the fruits of the Rosa rugosa are a desirable raw material for the production of fruit wine. The parameters of the technological process of producing wines from rose fruits had a diversified influence on the tested quality characteristics. Aged wines contained phenolics levels of 473–958 mg/100 mL GAE. The final concentrations of ascorbic acid ranged from 61 to 155 mg/100 mL for the different variants of the wine. Wines revealed high antioxidant activity in assay with DPPH. On the basis of the obtained results, it can be assumed that all the applied variants of the winemaking process are suitable for rose fruit wine. Each variant ensured at least the stability of the antioxidant capacity. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
The Effect of the Addition of Fiber Preparations on the Color of Medium-Grounded Pasteurized and Sterilized Model Canned Meat Products
Molecules 2021, 26(8), 2247; https://doi.org/10.3390/molecules26082247 - 13 Apr 2021
Cited by 1 | Viewed by 758
Abstract
A beneficial aspect of the use of fiber preparations in the meat industry is the improvement of some quality characteristics of meat products. However, the preparation added in the amount of 3 or 6% may affect their color. The effect of the addition [...] Read more.
A beneficial aspect of the use of fiber preparations in the meat industry is the improvement of some quality characteristics of meat products. However, the preparation added in the amount of 3 or 6% may affect their color. The effect of the addition of barley, wheat and oat fiber preparations with different fiber lengths, in quantities allowing the product to be indicated as “high in fiber” or “source of fiber”, to pasteurized or sterilized medium-grounded canned meat products on their color, was determined. In the obtained canned meat products, the basic chemical composition and the L*, a* and b*, C* (Chroma) and h* (hue angle) color components were determined. The addition of the barley fiber preparation BG 300 to the model canned meat products caused a significant (p ≤ 0.05) darkening and an increase in the proportion of yellow color. In an industrial practice, this may result in poorer consumer acceptance of the meat product. Fiber length of wheat and barley fiber had no effect on the color components of products. The 6% addition of the wheat fiber preparations WF 200R and WF 600R or the oat fiber preparations HF 200 and HF 600 caused an apparent lightening of their color (ΔE > 2) compared to the control products. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
The Quality of Infrared Rotary Dried Terebinth (Pistacia atlantica L.)-Optimization and Prediction Approach Using Response Surface Methodology
Molecules 2021, 26(7), 1999; https://doi.org/10.3390/molecules26071999 - 01 Apr 2021
Cited by 6 | Viewed by 827
Abstract
Most agricultural products are harvested with a moisture content that is not suitable for storage. Therefore, the products are subjected to a drying process to prevent spoilage. This study evaluates an infrared rotary dryer (IRRD) with three levels of infrared power (250, 500, [...] Read more.
Most agricultural products are harvested with a moisture content that is not suitable for storage. Therefore, the products are subjected to a drying process to prevent spoilage. This study evaluates an infrared rotary dryer (IRRD) with three levels of infrared power (250, 500, and 750 W) and three levels of rotation speed (5, 10, and 15 rpm) to dry terebinth. Response surface methodology (RSM) was used to illustrate and optimize the interaction between the independent variables (infrared power and rotation speed) and the response variables (drying time, moisture diffusivity, shrinkage, color change, rehydration rate, total phenolic content, and antioxidant activity). As infrared power and rotation speed increased, drying time, rehydration rate, antioxidant activity, and total phenolic content decreased, while the other parameters were increased. According to the results, the optimum drying conditions of terebinth were determined in the IRRD at an infrared power of 250 W and drum rotation speed of 5 rpm. The optimum values of the response variables were 49.5 min for drying time, 8.27 × 10−9 m2/s for effective moisture diffusivity, 2.26 for lightness, 21.60 for total color changes, 34.75% for shrinkage, 2.4 for rehydration rate, 124.76 mg GAE/g d.m. for total phenolic content and 81% for antioxidant activity. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
Impact of High-Pressure Homogenization Parameters on Physicochemical Characteristics, Bioactive Compounds Content, and Antioxidant Capacity of Blackcurrant Juice
Molecules 2021, 26(6), 1802; https://doi.org/10.3390/molecules26061802 - 23 Mar 2021
Cited by 8 | Viewed by 870
Abstract
High-pressure homogenization (HPH) is one of the food-processing methods being tested for use in food preservation as an alternative to pasteurization. The effects of the HPH process on food can vary depending on the process parameters used and product characteristics. The study aimed [...] Read more.
High-pressure homogenization (HPH) is one of the food-processing methods being tested for use in food preservation as an alternative to pasteurization. The effects of the HPH process on food can vary depending on the process parameters used and product characteristics. The study aimed to investigate the effect of pressure, the number of passes, and the inlet temperature of HPH processing on the quality of cloudy blackcurrant juice as an example of food rich in bioactive compounds. For this purpose, the HPH treatment (pressure of 50, 150, and 220 MPa; one, three, and five passes; inlet temperature at 4 and 20 °C) and the pasteurization of the juice were performed. Titratable acidity, pH, turbidity, anthocyanin, vitamin C, and total phenolics content, as well as colour, and antioxidant activity were measured. Heat treatment significantly decreased the quality of the juice. For processing of the juice, the best were the combinations of the following: one pass, the inlet temperature of 4 °C, any of the used pressures (50, 150, and 220 MPa); and one pass, the inlet temperature of 20 °C, and the pressure of 150 MPa. Vitamin C and anthocyanin degradation have been reported during the HPH. The multiple passes of the juice through the machine were only beneficial in increasing the antioxidant capacity but negatively affected the colour stability. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
Physical, Thermal and Biological Properties of Yellow Dyes with Two Azodiphenylether Groups of Anthracene
Molecules 2020, 25(23), 5757; https://doi.org/10.3390/molecules25235757 - 06 Dec 2020
Cited by 1 | Viewed by 1415
Abstract
Two yellow bis-azo dyes containing anthracene and two azodiphenylether groups (BPA and BTA) were prepared, and an extensive investigation of their physical, thermal and biological properties was carried out. The chemical structure was confirmed by the FTIR spectra, while from the UV–Vis spectra, [...] Read more.
Two yellow bis-azo dyes containing anthracene and two azodiphenylether groups (BPA and BTA) were prepared, and an extensive investigation of their physical, thermal and biological properties was carried out. The chemical structure was confirmed by the FTIR spectra, while from the UV–Vis spectra, the quantum efficiency of the laser fluorescence at the 476.5 nm was determined to be 0.33 (BPA) and 0.50 (BTA). The possible transitions between the energy levels of the electrons of the chemical elements were established, identifying the energies and the electronic configurations of the levels of transition. Both crystals are anisotropic, the optical phenomenon of double refraction of polarized light (birefringence) taking place. Images of maximum illumination and extinction were recorded when the crystals of the bis-azo compounds rotated by 90° each, which confirms their birefringence. A morphologic study of the thin films deposited onto glass surfaces was performed, proving the good adhesion of both dyes. By thermal analysis and calorimetry, the melting temperatures were determined (~224–225 °C for both of them), as well as their decomposition pathways and thermal effects (enthalpy variations during undergoing processes); thus, good thermal stability was exhibited. The interaction of the two compounds with collagen in the suede was studied, as well as their antioxidant activity, advocating for good chemical stability and potential to be safely used as coloring agents in the food industry. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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Article
The Influence of Temperature Differences in Smoking Chamber and Furnace and Smoking Time on the Quality of Medium-Ground Sausages
Molecules 2020, 25(23), 5515; https://doi.org/10.3390/molecules25235515 - 25 Nov 2020
Cited by 1 | Viewed by 710
Abstract
The aim of the work was to determine the impact of two variants (A and B) of smoking (differing in temperature values, furnace, top and bottom of the smoking chamber and the length of smoking time) in the sausage technological process carried out [...] Read more.
The aim of the work was to determine the impact of two variants (A and B) of smoking (differing in temperature values, furnace, top and bottom of the smoking chamber and the length of smoking time) in the sausage technological process carried out in a traditional smoking chamber with an indirect furnace. The research material consisted of medium-ground sausages: Country, Home and Bieszczady sausages. The research showed that, as the temperature in the smoking chamber and the smoking time changed, the following texture parameters decreased: cycle hardness 1 and 2, springiness, gumminess and chewiness. In addition, there were shown statistically significant differences (p < 0.05) in the chemical composition of Country sausage between the applied smoking variants. It was also found that the temperature of the furnace, upper and lower smoking chamber and the length of smoking time did not have a statistically significant influence on the share of red (a*) and yellow (b*) in the analysed sausages. Full article
(This article belongs to the Special Issue Colorants Changes during Food Treatment and Processing)
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