Evaluation of carbon dioxide elevation on phenolic compounds and antioxidant activity of red onion (Allium cepa L.) during postharvest storage.

Carbon dioxide (CO2) is considered one of the eco-related key factors that negatively affect global climatic change. Also, CO2 can play an important role in the postharvest quality of the agri-products. In this study, the impact of CO2 on the quality of postharvest onions that were stored at 23 °C for 8 weeks was investigated. The weight loss, phenolic, flavonoid, flavanol, anthocyanin, antioxidant activity, and soluble sugar were analyzed during the study period. The results showed that 20% CO2 treatment was significantly (P > 0.05) more effective than 15% CO2 and control in inhibiting weight loss. Additionally, 20% CO2 treatment significantly retained higher antioxidant enzyme activities such as CAT, APX, and SOD than 15% CO2 and control. During storage, 20% CO2 treatment significantly (P < 0.05) improved glucose, fructose, and sucrose levels by more than 15% CO2 exposure and control groups. Besides the chlorogenic acid, kaempferol and quercetin were significantly (P < 0.05) higher in the 20% CO2 than in the 15% CO2 after 2 weeks of storage. In conclusion, this study's novelty comes from the broad prospects of using CO2 for maximizing the stored onion phytochemical functionality that is usually affected by the room temperature long storage. This will help in the onion shelf-life extension by considering the quality-related attributes.

A new natural drying method for food packaging and preservation using biopolymer-based dehydration film.

A new method for the drying of beef and chicken meats at low temperatures (4 °C) was developed by using a composite film based on sodium carboxymethyl cellulose-gum Arabic (SG) with anthocyanins from Cinnamomum camphora fruit peel (ANC.P, 0, 1, 1.5 and 2%). After incorporation of ANC.P into SG, the physicochemical properties, morphological characteristics, melting, molecular, antioxidant and antimicrobial properties of the resulting dehydration films were improved. Film-dried beef and chicken slices showed higher values of dehydration ratio on day 6 (54.58% and 72.06%, respectively) compared with the control samples without film (4.55% and 7.04%, respectively). Results showed that SG-ANC.P film-dried meats exhibited more stable pH and color, higher rehydration rate, better sensory quality and microbial growth inhibition compared with SG film-dried samples and control samples, in which control samples showed the highest total viable count values (6.02 and 5.16 log CFU/mL for beef and chicken, respectively) during storage.

Characterisation of Flavour Attributes in Egg White Protein Using HS-GC-IMS Combined with E-Nose and E-Tongue: Effect of High-Voltage Cold Plasma Treatment Time.

Egg white protein (EWP) is susceptible to denaturation and coagulation when exposed to high temperatures, adversely affecting its flavour, thereby influencing consumers' decisions. Here, we employ high-voltage cold plasma (HVCP) as a novel nonthermal technique to investigate its influence on the EWP's flavour attributes using E-nose, E-tongue, and headspace gas-chromatography-ion-mobilisation spectrometry (HS-GC-IMS) due to their rapidness and high sensitivity in identifying flavour fingerprints in foods. The EWP was investigated at 0, 60, 120, 180, 240, and 300 s of HVCP treatment time. The results revealed that HVCP significantly influences the odour and taste attributes of the EWP across all treatments, with a more significant influence at 60 and 120 s of HVCP treatment. Principal component analyses of the E-nose and E-tongue clearly distinguish the odour and taste sensors' responses. The HS-GC-IMS analysis identified 65 volatile compounds across the treatments. The volatile compounds' concentrations increased as the HVCP treatment time was increased from 0 to 300 s. The significant compounds contributing to EWP characterisation include heptanal, ethylbenzene, ethanol, acetic acid, nonanal, heptacosane, 5-octadecanal, decanal, p-xylene, and octanal. Thus, this study shows that HVCP could be utilised to modify and improve the EWP flavour attributes.

Dielectric barrier discharge cold atmospheric plasma: Influence of processing parameters on microbial inactivation in meat and meat products.

Decontamination of meat is commonly practiced to get rid of or decrease the microbial presence on the meat surface. Dielectric barrier discharge cold atmospheric plasma (DBD-CAP) as innovative technology is a food microbial inactivation technique considered in high regard by food scientists and engineers in present times. However, cold atmospheric plasma application is at the experimental stage, due to lack of sufficient information on its mode of action in inactivating microbes, food shelf-life extensibility, whereas, the nutritional value of food is preserved. In this review, we have appraised recent work on DBD-CAP concerning the decontamination treatment of meat products, highlighting the processing value results on the efficacy of the DBD-CAP microbial inactivation technique. Also, the paper will review the configurations, proposed mechanisms, and chemistry of DBD-CAP. Satisfactory microbial inactivation was observed. In terms of DBD-CAP application on sensory evaluation, inferences from reviewed literature showed that DBD has no significant effect on meat color and tenderness, whereas in contrast, TBARS values of fresh and processed meat are affected. DBD seems economically efficient and environmentally sustainable.

Effects of partial NaCl substitution with high-temperature ripening on proteolysis and volatile compounds during process of Chinese dry-cured lamb ham.

The effects of partial NaCl substitution combined with high-temperature ripening on the proteolysis and formation of volatile compounds in dry-cured lamb ham was investigated. Two salt treatments, I (0% KCl + 100% NaCl) and II (25% KCl + 75% NaCl), were considered. Although some studies have analyzed the influences of salt substitution on volatile compounds of dry-cured ham, no studies have evaluated lamb ham produced in China. Intensifying the high-temperature ripening lead to an increase in the formation of flavors generated by the Maillard reaction and Strecker degradation in both treatments, also, had a positive influence on proteolysis index and content of total free amino acids during the ripening stage. The application of 25% KCl did not influence the formation of volatiles during curing stage, however, there were more volatiles came from amino acids degradation in the final products with 25% KCl. Therefore, sodium reduction combined with high-temperature ripening may be an alternative method to manufacture Chinese dry-cured lamb hams.

Changes in color, myoglobin, and lipid oxidation in beef patties treated by dielectric barrier discharge cold plasma during storage.

The objective of this work was to investigate the changes in color, metmyoglobin reducing activity (MRA), and lipid oxidation (TBARS) and their relationships in beef patties treated by dielectric barrier discharge cold plasma (DBD-CP) at different voltages and frequencies during storage at 4 °C. DBD-CP treatment, including treatment voltages and frequencies, caused the decrease of a⁎ value and MRA (P < 0.05), promoted the accumulation of metmyoglobin (P < 0.05), and significantly increased TBARS values (P < 0.05). It was the first time revealed that the effect of treatment voltage on the quality of beef patty was greater than that of frequency. In addition, there were significant and strong positive correlations between a⁎ value and MRA and negative correlations between a⁎ value, metmyoglobin (MMb)% and TBARS. Taken together, Data demonstrated that DBD-CP treatment can significantly affect meat redness, Mb contents, MRA, and lipid oxidation in ground beef during storage, and accelerate discoloration and lipid oxidation of meat.

Atmospheric cold plasma treatment of soybean protein isolate: insights into the structural, physicochemical, and allergenic characteristics.

Currently, there has been a surge of interest in revealing the interactions between plasma and food matrices. In this study, we investigated the impacts of atmospheric cold plasma (ACP) treatment on the structural, physicochemical and allergenic characteristics of soybean protein isolate (SPI). SPI dispersions were subjected to ACP treatments at different frequencies (80 to 100 Hz) and durations (1 to 10 min) to investigate the effects of exposing conditions. Results showed that ACP induced reactive oxygen species-mediated oxidation of soy proteins, resulting in modifications in the secondary and ternary structures of SPI. As a consequence, functional properties of SPI, such as emulsifying (56 to 168%, compared with control) and foaming properties (60 to 194%) were influenced by varying degrees. In addition, under certain circumstance (120 Hz, 5 min), the IgE-binding level of SPI was decreased by up to 75%, when compared to the control. Moderate treatment yielded products with improved functionality and reduced allergenicity, while extensive exposure induced a loss of vendibility due to protein aggregation. PRACTICAL APPLICATION: In this study, we demonstrated for the first time, that plasma species reacted with soybean proteins, resulting in spatial structural changes which are closely related with protein functionality and allergenicity. ACP interacts with macromolecules in aqueous systems and thus can be an alternative and promising nonthermal approach in modifying soybean proteins, whereas the exact role of different processing parameters needs to be well-elaborated.

Exploring the Potential of High-Voltage Electric Field Cold Plasma (HVCP) Using a Dielectric Barrier Discharge (DBD) as a Plasma Source on the Quality Parameters of Carrot Juice.

The main aim of the current investigation was to contemplate the impact of high-voltage electric field cold plasma (HVCP) on different quality characteristics (enzymes, microbial activities, coloring pigments, ascorbic acid, polyphenolic compounds, °Brix, acidity, and color index) of carrot juice in correlation with thermal processing. A carrot juice (250 mL) sample sealed in pre-sterilized food-grade bottles, which placed between two dielectric quartz plates for HVCP treatment. The gap between the plates was 30 mm, and a stable and uniform plasma dielectric barrier discharge (DBD) generated for 3 and 4 min at 60, 70, and 80 kV. Air was used as a working gas during the DBD-based plasma treatment. The observed rise in temperature was 2-5 °C during the HVCP treatment. A water bath was used to carry out thermal treatment (100 °C for 5 min). The maximum inactivation of enzymes and microorganisms was achieved with thermal treatment and then with HVCP treatment at 70 kV for 4 min. However, maximum retention of coloring compounds, ascorbic acid, total phenols, flavonoids, and tannins was found following HVCP (70 kV for 4 min) treatment compared to thermal treatment. The °Brix, pH, and acidity remained unchanged irrespective of treatments. These findings suggest that HVCP treatment at 70 kV for 4 min may be a good alternative to thermal treatment, and it may successfully be applied in carrot juice production, resulting in reduced enzymes, lower microbial activity, and improved bioactive compounds. The prospects of overcoming the existing conventional physical and chemical methods for sterilization make it a novel and more economical technique to maintain food's natural nourishment, composition, appearance, structure, and freshness.

Evaluation of physicochemical properties and volatile compounds of Chinese dried pork loin curing with plasma-treated water brine.

The application of dielectric barrier discharge cold plasma (DBD-CP)-treated water as a novel curing process for manufacturing Chinese dried pork loin was investigated. The treatment time of DBD-CP was optimized based on the pH and nitrite level of the plasma-treated water (PTW). PTW treated for 3 min had an alkaline environment and a higher nitrite content than that at the other lengths of treatment time. Pork loins were marinated in control or PTW brine at 4 °C for 24 h and then dry-ripened for 15 days. PTW with a higher treatment voltage significantly decreased lipid oxidation of the products and led to an increased a* value (redness) and an increased residual nitrite content in products that was still within the range of use (all P < 0.05). The contents of each free amino acid increased with increasing treatment intensity (P < 0.05). There were 22 new volatile compounds generated in PTW-cured products, such as 3-methyl-butanol, hexanal and 2,3-octanedione, while six substances were lost, such as 2-pentylfuran, compared with those in the control. This study indicates that using PTW as a curing method can be a potential and effective way of producing dried pork meat products.