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Novel Antioxidant Active Packaging Approach: Combination of Aquafaba and Essential Oil to Prevent Lipid Oxidation in Fish

Active packaging has commonly consisted of several bioactive compounds that improve sensory characteristics, protect quality, and extend the shelf life of food products. With a better understanding of the importance of plant-based protein sources, the utilization of by-products of any food item has taken interest in both academia and industry. Aquafaba, as an accepted legume by-product, offers several benefits in the food industry owing to its gelling property and high emulsifier and stabilizer capacity. Over the years, essential oils have been used as an antioxidant agent in the active packaging approach to prevent lipid oxidation, especially in highly perishable foods. Edible films are produced with lyophilized aquafaba from chickpeas and lemon essential oil at 1.0, 1.5, and 2.0%. Sea bream fillets coated with aquafaba, and lemon essential oil contained edible film and were stored in a refrigerator (at 4°C) for 13 days. A non-coated sample and only aquafaba containing edible film were considered negative and positive controls, respectively. The antioxidant capacity of edible films was controlled by the DPPH method, and the lipid oxidation in coated sea bream was determined by TBA analyses during storage. The results clearly indicate that the highest antioxidant capacity was found in the edible film containing lemon essential oil at the 1.5% level. The results of TBA analyses showed that the antioxidant capacity of aquafaba edible oil without lemon essential oil addition was at its lowest ratio. The higher antioxidant capacity of edible aquafaba film prevents lipid oxidation in the sea bream. The developed aquafaba lemon essential oil edible films have the potential to be used as active antioxidant packaging in the food industry, especially for highly perishable food items.

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INSTRUMENTAL EVALUATION OF SELECTED PROPERTIES OF OIL EXTRACTED FROM WALNUTS BEFORE AND AFTER THE ROASTING PROCESS

Nowadays consumers are increasingly looking for alternatives to animal fats. Fats are a source of energy for the body, in addition to being a source of essential fatty acids (EFAs). The composition of the fatty acids determines the nutritional value of the fat.
Walnuts (Juglans regia) have a high fat content of approximately 73%. The oil contained in the nuts is rich in unsaturated fatty acids, including monounsaturated oleic acid and polyunsaturated fatty acids, both of the n-3 and n-6 family. One important thermal process for nuts is roasting, which significantly increases their palatability. Technically, roasting is a drying process at high temperatures. The purpose of roasting is to reveal new flavour and aroma properties of the raw material.
The aim of the current study was to determine and compare the fatty acid composition and oxidative and hydrolytic stability of oils extracted from both roasted and raw walnuts.
The walnuts, which were purchased from the Polish market, were roasted at 100 and 160°C for 9 and 60 minutes (4 sets of conditions in total). Roasting of whole walnuts in a thin layer was carried out in a laboratory oven and repeated twice at each condition. After roasting, the nut oil was extracted with hexane. The following parameters of the extracted oil were determined: fatty acid composition (by gas chromatography), and acid and peroxide number (by titration). The oxidative stability of the oil was determined using a DSC calorimeter equipped with a high-pressure cell (PDSC). Samples were placed in aluminium vessels filled with oxygen, pressurised in an isobaric module (1400 kPa) with the temperature set at 120°C. The oxidation induction time was read from the PDSC curves.
The results indicate that hydrolytic stability decreased after roasting, as a slight increase in acid number was recorded in the oil extracted from roasted walnuts. Oil extracted from walnuts roasted at 100°C had the highest acid number. The oxidative stability of the walnut oil after roasting did not change significantly. The low oxidative stability of walnut oil may be related to the high content of polyunsaturated fatty acids (about 70%).

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Sensory profile of gluten-free breads based on alternative commercial flours

Gluten-free breads (GFB) are based mainly on refined flours, being characterised by a poor nutritional profile. The use of alternative flours, rich in protein and dietary fibre in the design of GFB could improve either technological or nutritional properties. The objective of the study was to evaluate the global differences/similarities, and the overall acceptability of GFB formulated with alternative flours in regular consumers and with gluten-related disorders. A projective mapping and hedonic test were used to describe the sensory profile and to assess the liking of products in untrained panellists (N=34). GFB were formulated using a traditional recipe, where 20% of refined flours were replaced by: brown rice, rice bran, lupin, millet, carob, quinoa, sorghum, teff or buckwheat. The hydration level and fermentation time were previously optimised to maximise the GFB specific volume. The relationship between products and descriptors was analysed by a multiple factor analysis (MFA) using XLSTAT software. The results showed four different groups of GFB based on (1) carob which was described as acid, (2) millet as white crumb, (3) rice bran, sorghum, lupin and buckwheat as crumbly and smelly, and (4) teff, quinoa and brown rice as sweet, springy and crispy. GFB received a punctuation of 5.9-7.3 in a 9-point scale, being the GFB based on carob flour the less accepted (2.9±2.5). These flours could contribute to enhancing the nutritional profile and could be a useful tool for the food industry. GFB formulations should be optimised for improving the consumer acceptability according to the flour selected.

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Evaluation of DNA extraction methods for PCR analysis of maize and sunflower oils
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Vegetable oils are an important source of energy and are often used in human nutrition. The modern food industry has a big challenge dealing with adulteration of different types of plant oils. Reliable authentication of oils is essential for food quality and safety assessment, correct labeling, sustainable food production, and health protection. DNA-based polymerase chain reaction (PCR) techniques are recognized as the most efficient means of reliable food analysis. Preparation of DNA samples of appropriate quality and in sufficient quantities from oils remains the major drawback for successful PCR detection. This study examines several approaches to DNA enrichment and extraction. Four DNA extraction methods were used, such as two types of our modified CTAB methods, the NucleoSpin Food Mini Kit, and the Olive Oil DNA Isolation Kit. Various cold-pressed and refined oils of corn and sunflower were tested. DNAs were evaluated by spectrophotometer and PCR analysis. DNA amplification was performed with eukaryote, plant, and species-specific PCR systems. PCR products were evaluated by agarose gel electrophoresis. The obtained results indicate the importance of oil quality, DNA isolation, and amplification methods for successful PCR results. The outcomes of the study revealed the advantages and limitations of each DNA extraction method. An optimized procedure for plant DNA traceability in oils using PCR technology has been developed.

Acknowledgments

This work was supported by Shota Rustaveli National Science Foundation of Georgia (SRNSFG) [Grant AR-22- 636].

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Human risks to vanadium from naturally growing edible mushrooms and topsoils across Leicestershire, UK

Essentiality of vanadium (V) has been proven for some terrestrial fungi. Thus, some wild mushrooms can accumulate high amounts of this element, such as the poisonous species of Amanita. The aims of our work were: a) to biomonitor V in wild edible mushrooms collected from urban and rural green areas across Leicester, a main city in East Midlands (England); and b) to determine the presence and distribution of V in topsoils to identify potential risks to humans. A total of 34 edible mushrooms were collected as follows: twenty-two Agaricus bitorquis were collected from an open green area close to St Augustine Road, a high traffic area close to the city centre, four Marasmius oreades from Jesse Jackson Park in the northeast of the city, and eight Coprinus atramentarius from Bradgate Park, a 850 acre public park in Charnwood Forest, Leicestershire (northwest of Leicester city). Although C. atramentarius has been described as poisonous, this mushroom species are edible and safe if cooked and if no alcohol is ingested within 2–3 days of eating C. atramentarius. Species identification was confirmed by DNA barcoding using internal transcribed spacer 1/4 primers after extracting DNA from 100 mg of frozen homogenised ground mushroom material using DNeasy Plant Mini Kit®. V was monitored by ICP-MS in cleaned, dried and homogenised mushrooms mineralised with HNO3/H2O2 [LoD=0.062 mg/kg dry weight (dw)]. Significantly higher levels of V were found in C. atramentarius [0.856 (0.175-4.338)] than in the edible mushrooms collected in urban areas [M. oreades 0.305 (<LoD-0.852) and A. bitorquis 0.078 (<LoD-0.187); all data presented as median and range, in mg/kg dw; p-value=2E-07]. In general, the levels of V found were similar to those reported in twelve different edible mushroom species collected in Finland (range reported 0.04-0.33 mg/kg dw), although some of the eight C. atramentarius mushrooms collected presented very high levels of this metal. Thus, despite the health risk quotients calculated (7.06E-10, 2.76E-09, 7.74E-09; for A. bitorquis, M. oreades and C. atramentarius, respectively) suggesting a minimal risk, consuming C. atramentarius mushrooms should be avoided even though if these mushroom species are properly cooked. Moreover, 850 samples were collected (2017-18), which were further processed as composite samples as follows: 26 composite samples were appropriately prepared after mixing topsoil samples collected per location (18 urban, 8 rural), which were further processed in duplicate. V was measured twice in each of the 52 composite samples by ICP-MS after microwave digestion with nitric acid (69%)/chlorhydric acid (37%). V was found in all composites examined (LoD=0.137 mg/kg). Significantly higher levels were found in the rural areas [61.403 (36.029-99.806) vs. 46.279 (25.861-84.653); data presented as median and range, in mg/kg; p-value=3E-05)], which might be attributed to geogenic sources as the enrichment factor for rural topsoils suggest minimal enrichment (EF=0.0046-1.690). Although the levels of V in the topsoils were much higher than the established soil screening value for assessing ecological risks (SSV=2 mg/kg) established by the UK’s Environment Agency. The presence of this metal in the topsoils monitored in the urban and rural areas of Leicestershire would not represent a significant risk for the population, as the hazard quotients for oral, dermal and inhalation exposure to V present in topsoils were much lower than the threshold considered as safe for adults and children. Moreover, the bioconcentration potential of the wild mushroom species collected for V would be minimal as the bioconcentration factors were much lower than the unit in relation to the concentration of V in the underlying topsoils. Although the three wild edible mushroom species monitored in Leicestershire could be considered as bioexcluders of vanadium, the high concentration of this element in some of the mushrooms collected would recommend avoidance of consumption as they may also concentrate other toxic and carcinogenic metals that would add to the identified risk.

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Immature Opuntia ficus indica peel by-product as a mayonnaise additive and natural anticoccidial drug

In recent years, the valorization of food by-products has attracted increased interest in the scientific community for ecological and economic reasons. Opuntia ficus-indica (OFI) peels are the primary by-product of prickly pears. Several studies claim that the beneficial bioactive compounds are concentrated in the fruit's peel. Therefore, the present investigation aimed to study OFI peel immature as a natural antioxidant in mayonnaise and its use as a natural treatment against coccidiosis, which is the main disease of broiler chickens. The finding confirmed that OFI peels are a source of phenolic compounds, including total phenolic compounds, flavonoids, tannins, and carotenoids (21.01±0.33, 1.12±0.28, 10.25±0.10 mg equivalent standard/g, and 5.62±0.53 mg β-carotene equivalent /100 g, respectively), having strong antioxidant activities over 87 percent (DPPH radical, iron chelation power, β-carotene bleaching). Using rancimat test OFI extract improves the mayonnaise's stability for 2.5 hours. Immature OFI peel extracts recorded a notable destruction rate of Eimeria oocysts. The current study promoted the use of immature OFI peel extracts as a natural food additive and as an antiparasitic treatment substitute.

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Ideas generation for new aquaculture products (Sea Bream and Prawns) developing using Focus Group by different participants profiles

Nowadays, people are expressing great concern about having a healthy diet. Aquaculture products are considered healthy and from a safe source. Likewise, there is reported low consumption of these processed products. In this context, the objective of this study was to generate a list of ideas for new aquaculture products based on two species: sea bream and prawns. To carry out this work, a qualitative study was conducted using the "Focus group" technique. Two sessions were held, with a total of 20 participants with different profiles: 1. Consumers (n=10), 2. Chefs (n=5), 3. Researchers in food science and technology (n=5). Correspondence analysis was carried out to establish relationships between the variables: participants´ profiles and aquaculture products proposed.

During the discussion sessions, the following topics were addressed: 1. Survey on the consumption of aquaculture products; 2. Exploration of recent launches of new food products; 3. Brainstorming new products for sea bream and prawns; 4. Grouping ideas by product technologies: fresh, dehydrated, canned, marinated, and fermented; 5. Analysis of all concepts. The Correspondence analysis for sea bream shows that consumers generate ideas more focused on fresh products, while chefs and researchers develop ideas related to processed products. For prawns, ideas about dehydrated products have been mentioned in all profiles.

With the obtained results, an experimental design will be conducted as part of a questionnaire aimed at global consumers to assess the acceptability of these new aquaculture products.

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Effect of the incorporation of Fucus spiralis phlorotannin-enriched extracts in homogenised preparations of fresh salmon patties during storage

Natural antioxidants derived from macroalgae have great potential for improving oxidative stability of food products. Fucus spiralis (F. spiralis) is a brown macroalgae rich in bioactive compounds, including phlorotannins that are polyphenols derived from phloroglucinol with important antioxidant properties.

A F. spiralis phlorotannin-enriched ethyl acetate extract was evaluated as natural antioxidant to extend the shelf-life of salmon homogenates, while comparing it to artificial antioxidant BHT. The extract was obtained by submitting F. spiralis biomass collected in summer to an extraction with ethanol:water, followed by a liquid-liquid fractionation with organic solvents (Almeida et al., 2021).

Atlantic salmon (Salmo salar) fillets were ground, and the minced salmon was divided into three equally distributed groups: G1 with the incorporation of 0.01% F. spiralis extract; G2 with the incorporation of 0.01% synthetic antioxidant BHT; and G3 as control group. The extract and BHT were dissolved in food grade ethanol/water mixture (80:20 v/v) and the same amount of solvent was added to the control group. For each treatment, salmon patties were shaped, wrapped with polyethylene film paper, and stored at 4 °C. Moisture, pH, colour, total volatile base nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) were analysed at days 0, 3, 7, 11, 15, and 21 of storage.

The addition of the algal extract did not show significant differences in the maintenance of pH and humidity of the samples throughout testing time (21 days) when compared to the samples with artificial antioxidant BHT and the control. However, the extract had a similar behavior to the artificial antioxidant BHT regarding the diminishing of deterioration compounds in fish (decrease of thiobarbituric acid reactive species TBARs) on the first days of the study (until day 11) when compared to the control. Relative to color alteration, none of the antioxidants decreased color loss, as no significant changes were observed in the measured parameters. Regarding the quantification of total volatile basic nitrogen (TVB-N), no significant difference was observed among treatments.

References:

Almeida, B, Barroso, S., Ferreira, A. S. D., Adão, P., Mendes, S., Gil, M. M. (2021). Seasonal Evaluation of Phlorotannin-Enriched Extracts from Brown Macroalgae Fucus spiralis, Molecules, 26, 4287.

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Nutritional and genetic assessment of Traditional Greek Wheat Varieties.

Research has highlighted the nutritional benefits of ancient grains, especially emmer (Triticum dicoccum) and einkorn (Triticum monococcum), compared to modern wheat varieties, focusing on their higher levels of antioxidants and phytochemicals [1-4]. In this study, grains from traditional old Greek wheat varieties were evaluated and compared to commercial cultivars, like Simeto and Mexicali 81, in an effort to assess differences and eventually valorize local products. The samples studied in this research included emmer and einkorn as well as common wheat and durum wheat grains. The Internal Transcribed Spacer 2 (ITS2) nuclear region was amplified and sequenced as a barcode for species identification, allowing einkorn discrimination. The total content of bound and free polyphenols and flavonoids, as well as the antioxidant activity of bound and free compounds was also determined. Additionally, the level of variation of fatty acids was determined in all samples by gas chromatography. The results showed that local old landraces of emmer and einkorn had the highest polyphenol content, 2.2 and 3.1 times higher than the average value of durum wheat, respectively. Regarding the total flavonoid content einkorn and emmer had higher content than common wheat. The antioxidant activity of free or bound compounds was of the same level, at about 20-25% higher in both einkorn and emmer compared to common wheat. The results of this study demonstrate the high nutritional value of old local landraces underlining the importance of maintaining genetic material able to perform in a low input and environmental sustainable agriculture.

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Inactivation of polygalacturonase by pulsed light, a kinetic and structural study

Polygalacturonase (PG) is one of the most important enzymes related to the quality of vegetables, fruits and their products, it catalyzes the degradation of pectin. Cloudy juices may lose their turbidity by the action of pectin methylesterase and PG; hence it is important to have efficient methods to inactivate them. Pulsed light (PL) is a non-thermal method for food preservation based on the use of pulses of a high-intensity wide-spectrum light. Its ability to inactivate food enzymes has been demonstrated and has been related to absorption of UV light by proteins. The aim of this study was to investigate the capability of PL to inactivate PG, its kinetic and associated structural changes measured by chemical and fluorometric methods. PL was able to inactivate PG with a first-order kinetic constant of 0.0426 cm2/J; requiring 128 J/cm2 to achieve 90 % inactivation. Disulfide bridges became broken during PL treatment as indicated by a 40 % increase in free sulfhydryl groups. Evidence of loss of tertiary structure was indicated by a decrease in intrinsic fluorescence intensity and changes in parameter A. The inactivation seems to proceed without transition states as observed in the phase-diagram analysis. In conclusion, PL is able to inactivate PG and the process is associated to rupture of disulfide bridges and changes in tertiary structure following a simple all-or-none process. Results show the capability of PL to inactivate PG, which may be useful to stabilize cloudy fruit juices.

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