Non-thermal Processing Method Research Articles

Improving the microbiological safety and quality of aquatic products using nonthermal processing.

Spoilage and deterioration of aquatic products during storage are inevitable, posing significant challenges to their suitability for consumption and the sustainability of the aquatic products supply chain. Research on the nonthermal processing of fruit juices, probiotics, dairy products, and meat has demonstrated positive outcomes in preserving quality. This review examines specific spoilage bacteria species and mechanisms for various aquatic products and discusses the principles, characteristics, and applications of six nonthermal processing methods for bacterial inhibition to maintain microbiological safety and physicochemical quality. The primary spoilage bacteria groups differ among fish, crustaceans, and shellfish based on storage conditions and durations. Four metabolic pathways utilized by spoilage microorganisms-peptides and amino acids, nitrogen compounds, nucleotides, and carbohydrates-are crucial in explaining spoilage. Nonthermal processing techniques, such as ultrahigh pressure, irradiation, magnetic/electric fields, plasma, and ultrasound, can inactivate microorganisms, thereby enhancing microbiological safety, physicochemical quality, and shelf life. Future research may integrate nonthermal processing with other technologies (e.g., modified atmosphere packaging and omics) to elucidate mechanisms of spoilage and improve the storage quality of aquatic products.

Application of pulsed electric field technology to skin engineering.

Tissue engineering encompasses a range of techniques that direct the growth of cells into a living tissue construct for regenerative medicine applications, disease models, drug discovery, and safety testing. These techniques have been implemented to alleviate the clinical burdens of impaired healing of skin, bone, and other tissues. Construct development requires the integration of tissue-specific cells and/or an extracellular matrix-mimicking biomaterial for structural support. Production of such constructs is generally expensive and environmentally costly, thus eco-sustainable approaches should be explored. Pulsed electric field (PEF) technology is a nonthermal physical processing method commonly used in food production and biomedical applications. In this review, the key principles of PEF and the application of PEF technology for skin engineering will be discussed, with an emphasis on how PEF can be applied to skin cells to modify their behaviour, and to biomaterials to assist in their isolation or sterilisation, or to modify their physical properties. The findings indicate that the success of PEF in tissue engineering will be reliant on systematic evaluation of key parameters, such as electric field strength, and their impact on different skin cell and biomaterial types. Linking tangible input parameters to biological responses critical to healing will assist with the development of PEF as a sustainable tool for skin repair and other tissue engineering applications.

Promoting the Aging Process and Enhancing the Production of Antioxidant Components of Garlic through Pulsed Electric Field Treatments.

Shortening the aging duration and enhancing the functional components of garlic present significant technical challenges that need to be addressed. Thus, this study aimed to evaluate the potential role of pulsed electric field (PEF) treatment, a novel nonthermal food processing method, in promoting and enhancing the functional attributes of aged garlic. Our results showed that 2-4 kV/cm PEF pretreatment increased S-allyl cysteine (SAC), total polyphenol (TPC), and flavonoid contents (TFC) compared with un-pretreated garlic during aging. The browning and texture-softening were also significantly improved during processing time, though the latter showed no significant difference from the eighth day to the end of the aging process. The principal component analysis results showed that PEF positively affects the SAC and TFC formations without adverse effects. Among the PEF pretreatments, 3 kV/cm is the most effective in enhancing functional component production compared with the other PEF pretreatments. Therefore, PEF pretreatment is a time-saving process that promotes and enhances the functionality of aged garlic.

Inactivation of microorganisms by high hydrostatic pressure: A literature review

The use of high hydrostatic pressure is intended to perform non-thermal inactivation of microorganisms in food products, to ensure their freshness and to prevent foodborne infections. These infections impact the healthcare system, the food industry, and consumers directly. This study aims to analyse the literature on the effectiveness of high hydrostatic pressure against pathogenic and opportunistic microorganisms transmitted through the consumption of contaminated food. Scientific publications for 2011-2023 were selected for the review. A total of 44 scientific publications were selected, the information from which was critically analysed, systematised and presented in the form of a literature review. The mechanisms of high hydrostatic pressure’s effect on microbial cells are described. To illustrate the effectiveness of high hydrostatic pressure against microorganisms, data from selected publications regarding efficiency and treatment parameters are presented in tables. The inactivation of such clinically important microorganisms as Bacillus cereus, Campylobacter jejuni, Clostridium perfringens, Escherichia coli, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus and Toxoplasma gondii in liquids and food has been demonstrated. High-pressure treatment has been shown to be a non-thermal food processing method, which distinguishes this method from traditional thermal processing methods such as boiling or pasteurization. One of the notable advantages of using high hydrostatic pressure is the non-thermal inactivation of various microorganisms, which preserves the nutritional and flavour properties of the processed product. It is also noted that food products can be processed in the final packaging, which reduces the risk of microbial contamination at the post-processing stages. The main disadvantages are the impossibility of complete inactivation of bacterial spores and the high cost of high-pressure processing equipment. Combining high-pressure treatment with other methods, such as heat treatment, can overcome the limitations of spore inactivation

The Impact of HPP-Assisted Biocontrol Approach on the Bacterial Communities' Dynamics and Quality Parameters of a Fermented Meat Sausage Model.

Traditional foods are increasingly valued by consumers, whose attention and purchase willingness are highly influenced by other claims such as 'natural', 'sustainable', and 'clean label'. The purpose of the present study was to evaluate the impact of a novel non-thermal food processing method (i.e., HPP-assisted biocontrol combining mild high hydrostatic pressure, listeriophage Listex, and pediocin PA-1 producing Pediococcus acidilactici) on the succession of bacterial communities and quality of a fermented sausage model. A comparative analysis of instrumental color, texture, and lipid peroxidation revealed no significant differences (p > 0.05) in these quality parameters between non- and minimally processed fermented sausages throughout 60-day refrigerated storage (4 °C). The microbiota dynamics of biotreated and untreated fermented sausages were assessed by 16S rRNA next-generation sequencing, and the alpha and beta diversity analyses revealed no dissimilarity in the structure and composition of the bacterial communities over the analyzed period. The innovative multi-hurdle technology proposed herein holds valuable potential for the manufacture of traditional fermented sausages while preserving their unique intrinsic characteristics.

Processing of Fresh-Cut Potato Using Plasma-Activated Water Prepared by Decreasing Discharge Frequency.

As a novel non-thermal processing method, the concentration of active compounds in plasma-activated water (PAW) is usually adjusted by changing the voltage and preparation time. We recently adjusted the discharge frequency and found that the PAW properties were improved. In this study, fresh-cut potato was selected as a model, and PAW was prepared using a frequency of 200 Hz (200 Hz-PAW). Its efficacy was compared with that of PAW prepared using 10 kHz. The results showed that the ozone, hydrogen peroxide, nitrate, and nitrite concentrations in 200 Hz-PAW were 5.00-, 3.62-, 8.05-, and 1.48-fold higher than those of 10 kHz-PAW. PAW inactivated the browning-related enzymes polyphenol oxidase and peroxidase, lowering the browning index and inhibiting browning; 200 Hz-PAW exhibited the lowest of these parameters during storage. In addition, PAW induced PAL to promote phenolic synthesis and increase antioxidant activity to delay malondialdehyde accumulation; 200 Hz-PAW exhibited the highest of these parameters. Moreover, 200 Hz-PAW had the lowest weight loss and electrolyte leakage rates. Furthermore, microbial analysis showed that the lowest aerobic mesophilic, mold, and yeast counts during storage were observed in the 200 Hz-PAW group. These results suggest that frequency-controlled PAW has the potential to treat fresh-cut produce.

Changes in advanced protein structure during dense phase carbon dioxide induced gel formation in golden pompano surimi correlate with gel strength

Changes in protein structure are closely related to gel strength. Dense phase carbon dioxide (DPCD) treatment is an excellent non-thermal food processing method that can be used to induce gel formation in surimi. The sensory, water holding capacity and gel strength of DPCD induced gels are superior to heat-induced gels. Fourier-transform infrared spectroscopy was used to investigate the role of DPCD in the quality of golden pompano surimi gels and changes in protein structure. The intermolecular forces of surimi gels were analyzed in terms of ionic and hydrogen bonds, disulfide covalent and non-disulfide covalent bonds, as well as hydrophobic interactions. Correlation analysis was used to investigate the relationship between the changes in advanced protein structure and gel strength during DPCD-induced gel formation in golden pompano surimi. The results showed that the α-helix and random coil levels of surimi gel were significantly decreased (p < 0.05), while the β-sheet and β-turn content was significantly increased (p < 0.05). The number of ionic and hydrogen bonds in gel proteins decreased significantly (p < 0.05), while the hydrophobic interactions, and disulfide and non-disulfide covalent bonds increased significantly (p < 0.05) after DPCD treatment. Correlation analysis showed that β-sheets, β-turns, hydrophobic interactions, and disulfide and non-disulfide covalent bonds were strongly positively correlated with gel strength, whereas α-helices, random coils, and ionic and hydrogen bonds were strongly negatively correlated with gel strength. Therefore, the α-helix and random coil structures of surimi gels were transformed into β-sheet and β-turn structures after DPCD treatment. Hydrophobic interactions, and disulfide and non-disulfide covalent bonds were the main intermolecular forces during the DPCD-induced gel formation of surimi. Ionic and hydrogen bonds were not the main intermolecular forces. The results provide fundamental data for elucidating the mechanism of DPCD-induced protein gel formation.

Design of a bipolar Dickson voltage multiplier suitable for low output voltage conditions to provide efficient food processing

There has been a growing demand for soft and nutritious foods in recent years. However, general food processing applies heat to food, which destroys nutrients in it. For this reason, many researchers have devised several non-thermal food processing methods so far. However, these methods have potential for improvement in terms of manufacturing cost and processing time. Thereby, we proposed the Dickson voltage multiplier which has bipolar topology suitable for low output voltage conditions in order to provide efficient food processing with low cost. The system is equipped with a high-speed driver using IGBTs, which allows the high-voltage multiplier to operate at high speed. In addition, by using Dickson multiplier with a bipolar topology, the voltage stress on each circuit component is reduced. Furthermore, we performed theoretical analysis to calculate the internal resistance and voltage gain of proposed multiplier. Moreover, we confirmed experimentally the possibility of the proposed multiplier by using the prototype.

Coconut water: production, nutritional properties and health benefits

Coconut water (Cocos nucifera L.) is an undiluted, non-fermented beverage obtained from the liquid part of the coconut fruit. It is a versatile product in the industry and has been growing economically due to its functional character. The objective is to identify in the scientific literature different aspects of coconut water production and its nutritional characteristics applied to health. A narrative review of the literature was carried out, using the databases Scielo, Scopus, Repositório Alice da EMBRAPA, Periódicos CAPES and Google academic, applying the descriptors, coconut water, nutrition, composition, health, health benefits, economy, pasteurization, ultrapressure, ultrasound, ozone and their respective names in English, considering the Boolean operators “OR” and “AND”. Titles and abstracts were screened, considering the eligibility criteria: full text available in English and/or Portuguese; paid and/or free access; dissertations and theses, narrative, systematic review, observational and longitudinal studies, including clinical trials. Non-thermal processing methods were effective in maintaining the shelf life of the beverage, however ultrapressure showed alterations in the physical functionality and/or changes in the color of protein-rich foods. The presence of phytohormones, vitamins and amino acids was detected, which are responsible for the antioxidant property of the product, as well as the beneficial effects on health. New studies are proposed to evaluate the effects of coconut water on human health, as it is a drink with market potential and accessible to consumers.

Modern non-thermal method of processing plant raw materials used to increase its storability

Along with thermal methods of processing plant raw materials, non-thermal processing methods have been actively developed in recent decades, which make it possible to preserve the qualitative characteristics of the initial raw materials to the maximum and increase the shelf life of the finished product. When using these methods, slight heating of the product can occur, for example, as in the processing by ultraviolet radiation (UVR). In the case of using such a type of processing as filtration, heating is completely absent; under the conditions of high pressure processing of the product (hereinafter HPP), a low temperature regime is observed. These methods are distinguished by minimizing the impact on the organoleptic characteristics of the finished product (texture, appearance, color, odor), as well as the preservation of micro- and macronutrients. The article discusses the main non-thermal methods of processing plant materials: high pressure (HPP), processing in a pulsed electric field (PEF), radioactive radiation, ultraviolet radiation (UVR), filtration. The advantages and factors hindering their widespread use on an industrial scale are noted. It is noted that high pressure, ultraviolet radiation and filtration to one degree or another are widely used in food production, while processing in a pulsed electric field and radioactive radiation are of extremely limited use due to the need to ensure the safety of processing for service personnel. It should also be noted that processing only by non-thermal methods leads to a limited shelf life of finished products and often requires lower storage temperatures. If it is necessary to increase the shelf life, it makes sense to combine thermal and non-thermal processing methods, for example, microfiltration (ultrafiltration) of juice, bottling into consumer packaging, gentle pasteurization. The undoubted advantage of this combination can be a reduction in the thermal load on a product, since the initial microbiological contamination is reduced by filtration. And, as a result, we get a stably stored product with minimal quality loss and preserved native potential.

Synergistic effect of UV-C irradiation and high-pressure processing in reducing microbial load in “Nanglae” pineapple juice compared to conventional heat treatment

Thermal processing is widely used in juice production to ensure microbial safety and to extend juice shelf life; however, it can have an impact on quality attributes such as color and nutritional content. UV-C irradiation and high-pressure processing (HPP) are non-thermal processing methods which causes little impact on the quality of fruit juice compared to conventional heat treatment (CHT). The objective of this study was to investigate the effect of combining UV-C and HPP (UV-C + HPP) treatments on microbial loads and quality of “Nanglae” pineapple juice during cold storage at 5 ± 1°C for 91 days. The treatments were as follows: (1) no treatment; (2) conventional heat treatment (80 ± 5°C, 10 min); and (3) a combination of UV-C (3 kJ/m2) and HPP (600 MPa, 5 min) treatments. The combined treatments of UV-C and HPP reduced the numbers of viable cells of aerobic microorganisms to less than the quantification limit of 1.48 log CFU/mL and yeasts and molds to <1.18 log CFU/mL throughout the 91-day storage period. Pineapple juice treated with CHT contained yeasts and molds exceeding the quantification limit of 1.18 log CFU/mL after 63 days of storage. The UV-C + HPP treatment preserved carotenoids and protein levels comparable to those found in fresh pineapple juice over 91 days of storage, whereas the CHT significantly decreased these values. Throughout the storage period, ascorbic acid levels in the CHT were slightly lower than in the combined treatments. These results clearly demonstrate that the combination of UV-C and HPP can ensure the safety of “Nanglae” pineapple juice while also retaining bioactive compounds. Combining these two technologies could be a new approach to producing healthy and safe juices.

Sustainable postharvest processing methods for millets: A review on its value‐added products

AbstractIn the era of climate change, where major crops like rice, wheat, maize are struggling to survive, millets (small seeded cereals), have been emerged as sustainable food sources to end hunger and poverty. They can grow well in harsh climatic conditions and being used as a major source of human food. They are better sources of proteins, fiber, minerals, carbohydrates, vitamins, essential amino acids, phytochemicals, and antioxidants than major cereals. The health beneficial properties of millets have challenged food engineers and technologists to mechanize the processes and to develop different value‐added products from them. Although millets are rich in nutrients but they need to be processed to remove antinutrient factors and to increase their nutrients availability. Various food processing methods like decortication/dehulling, milling, soaking, germination, malting, fermentation, puffing, and so forth are being employed these days for the millets to make them into the edible form and fit for human consumption. However, the nutrients and the functional properties of the grains get influenced by these food‐processing techniques. The present review endeavors to provide the insights into the nutritional and antinutritional characteristics of millets, various traditional and modern processing methods, which are being adopted to ease their processing and utilization in preparation of nutritious food products. The involvement of value‐added products of millets in our diets can ensure food and nutritional security.Practical applicationsThe processing of millets with sustainable thermal or nonthermal processing methods will not only make them fit for consumption but also enhance its nutritive value by reducing its antinutritional factors. The utilization of millets in different product development and the involvement of its value‐added products in our diets can ensure food and nutritional security.

Cold Atmospheric plasma treatments trigger changes in sun-dried tomatoes mycobiota by modifying the spore surface structure and hydrophobicity

The contamination of sun-dried tomatoes during processing can have a decisive impact on the quality of the finished product. In this study we investigated how Cold Atmospheric Plasma (CAP) under high surface power density (SPD) values can reduce fungal contamination in sun-dried tomatoes. In the application of this innovative processing method, the established “regime” for air plasma chemistry was the transition regime or NOx regime. First, we isolated and identified the mycobiota present on the tomatoes surfaces by mean of the analysis of the ITS region. The analysis revealed 32 different species, with A. niger , A. tubingensis, A. chevalieri , A. flavus, and A. alternata being the most abundant. Then, to reduce the fungal population, CAP-NOx was applied for 5, 10, 20 and 30 min on the surface of dried tomatoes. After incubation for 10 days, we observed that the antifungal effect was species and dose-dependent. In vitro investigation on the most abundant species revealed that A. chevalieri PSJ144 was the most sensitive species (almost 90%) immediately after 5 min of CAP treatment. With the increase of the exposure time up to 30 min, a strong reduction (p ≤ 0.05) of spore germination of A. alternata PSJ77 and A. tubingensis PSJ100 was observed (98 and 92%, respectively). However, spores of A. niger PSJ38 and A. flavus PSJ30 showed the highest resistance to the treatment. Moreover, the reparameterized Weibull function allowed to obtain useful information about germination kinetics as a function of time of CAP-NOx treatment, revealing that the resistance of the spores was: A. chevalieri < A. alternata < A. tubingensis < A . flavus < A. niger . In situ analyses confirmed a significant effect on natural fungal contamination by CAP-NOx treatment (76.5% of reduction), likely due to cell membrane rupture and cell death caused by plasma radicals. In addition, Pearson correlation analysis showed that spore resistance was highly correlated (p = 0.98) with their hydrophobicity. In a nutshell, our results clearly indicate that CAP-NOx treatment is an effective technique to reduce fungal contamination in sun-dried tomatoes. Among non-thermal processing methods, CAP shows promising perspectives of application in the tomato industry, to mitigate the effects of energy price rises. • A. niger , A. tubingensis, were most abundant species in dried tomatoes. • CAP reduced the fungal contamination on the dried tomatoes by 76.5%. • A. niger and A. flavus spores were more resistant ones to CAP. • A. chevalieri spores were inactivated after 0.1 min of CAP-NOx. • Spore hydrophobicity was correlated with the spore resistant to CAP.

Food processing to reduce antinutrients in plant-based foods

Antinutrients such as phytic acids, tannins, saponin, and enzyme inhibitors are phytochemicals that can decrease the bioavailability of micro- and macronutrients, thus causing them to be unavailable for absorptions in the digestive system. Antinutrients are a major concern especially in countries where plant-based commodities such as wheat, legumes, and cereals are staple foods, for the antinutrients can cause not only mineral deficiencies, but also lead to more serious health issues. Although various thermal and non-thermal processing methods such as cooking, boiling, and fermentation processes have been practiced to decrease the level of antinutrients, these processes may also undesirably influence the final products. More advanced practices, such as ozonation and cold plasma processing (CPP), have been applied to decrease the antinutrients without majorly affecting the physicochemical and nutritional aspects of the commodities post-processing. This review will cover the types of antinutrients that are commonly found in plants, and the available processing methods that can be used, either singly or in combination, to significantly decrease the antinutrients, thus rendering the foods safe for consumption.

Effect of plasma‐activated water treatment on physicochemical and functional properties of whey protein isolate

SummaryPlasma‐activated water (PAW) is an emerging nonthermal processing method explored for its food disinfection properties. However, the effect of reactive species in PAW on the food composition has not yet been studied. In this study, a simple protein, whey protein isolate (WPI) was used to understand the effect of PAW reactive species on its physicochemical and functional properties. The results showed mild oxidation of WPI evidenced from the decrease in the sulfhydryl group content and increase in the surface hydrophobicity. Increase in the soluble protein content was observed with PAW 45 min treatment. Foam stability of the PAW‐treated samples increased significantly following PAW treatment. However, no linear change in WPI properties was observed with PAW treatment time. Reduction in the thermal stability of samples was observed in 10 and 50 mg mL−1 concentrations with PAW treatment. The SDS‐PAGE analysis revealed that PAW treatment did not form in‐soluble protein aggregation in WPI samples. FTIR spectrum of the treated WPI samples showed that there were no new functional groups formed by the PAW treatment. Increase in β‐sheet, random coil percentage and reduction in α‐helix percentage was observed in 5 mg mL−1 concentration. The results suggest that the reactive oxygen species in the PAW lead to mild oxidation and unfolding of the WPI samples and improved its foam stability.

Formation of hydroxyphenyl-pyranoanthocyanins derived from cyanidin-3-O-glucoside and effects of high-pressure processing on the transformation efficiency

Hydroxyphenyl-pyranoanthocyanins (PACNs), derived from anthocyanins (ACNs) reacted with hydroxycinnamic acids, have higher practical application value because of better physicochemical stability than their precursors. However, the slow formation rate restricted their broader applications. In the present study, cyanidin-3-O-glucoside (C3G) was chosen to react with four kinds of hydroxycinnamic acids in a model solution. Changes of color and the production of hydroxyphenyl-PACNs were monitored. The formation of derivatives was time-dependent, and the orange-yellow changing trend was correlated with the formation of PACNs and the consumption of C3G. In addition, high-pressure processing (HPP) as a widely-used non-thermal processing method in the food industry was conducted to investigate its impact on hydroxyphenyl-PACNs formation. The results showed that HPP significantly improves the yield of two types of hydroxyphenyl-PACNs (C3G-4-vinylcatechol and C3G-4-vinylphenol) and the retention of total residual pigments during 56 days of storage. Therefore, HPP contributed to color-protecting and the transformation of hydroxyphenyl-PACNs.

Glucosinolates breakdown and enhanced nitrile formation in gamma irradiated minimally processed cauliflower (Brassica oleracia)

Glucosinolates (GSLs) and its degradation products from Brassica vegetables are of special importance due to diverse biological activities including health benefits. Gamma irradiation (a non-thermal post-harvest processing method) is known to extend shelf life of minimally processed cauliflower. However, the effect of gamma radiation on GSLs content and their hydrolytic products such as nitriles is less understood. In the current study, the mechanism of enhanced breakdown of major GSLs (sinigrin, glucoiberin and glucobrassicin) and formation of nitriles due to gamma irradiation was elucidated. The nitrile formation due to radiation stress was shown to be mediated by improved Fe2+ availability. The significant enhancement of nitrile formation was observed during Fe2+ supplementation studies. Gamma irradiation resulted in increase in total phenolic contents (35%), free radical scavenging activity (44%), and ferric reducing antioxidant power (FRAP) by 30%. The higher Fe2+ content was also observed in irradiated cauliflower and was maintained due to higher antioxidants (total phenolic contents) content. The change in expression of genes associated with GSLs biosynthesis was found to be not significant. Our study has illustrated the genetic and biochemical basis of GSLs reduction under radiation stress with special emphasis on role of Fe2+ in GSL metabolism after gamma irradiation.

Dynamics of high hydrostatic pressure resistance development in RpoS-deficient Escherichia coli

High hydrostatic pressure (HHP) treatment is one of the most widely accepted non-thermal food processing methods, but HHP-resistance development in pathogenic or spoilage bacteria might compromise the safety and stability of HHP-treated foods. Charting the possible routes and mechanisms of HHP resistance development in foodborne bacteria is therefore essential to anticipate or prevent the appearance of resistant variants. While upregulation of the RpoS-governed general stress response is a well-established route for increased HHP resistance in Escherichia coli, previous work revealed that mutations causing attenuated cAMP/CRP activity or aggregation-prone TnaA variants can evolve to overcome the HHP-hypersensitivity of an E. coli ΔrpoS mutant. In this study, further directed evolution and genetic analysis approaches allowed us to demonstrate that both kinds of mutants tend to co-emerge and compete with each other in E. coli ΔrpoS populations evolving towards HHP resistance, because of the higher HHP resistance of cAMP/CRP mutants and the faster growth rate of the TnaA mutants. Moreover, closer scrutiny of evolving populations revealed RpoS, cAMP/CRP and TnaA independent routes of HHP resistance development, based on downregulation of YegW or RppH activity.

Effects of Non-Thermal Processing Methods on Physicochemical, Bioactive, and Microbiological Properties of Fresh Pineapple (Ananas comosus L. Merr.) Juice

Background: Pineapple juice processing is an art of preservation, and the processing technologies play important role in pineapple juice quality. Therefore, this study aimed to explore the potential impacts of non-thermal processing methods on the physicochemical, bioactive, and microbiological properties of fresh pineapple juice.&#x0D; Methods: Extracted juices were subjected to several non-thermal processes including microwave processing, vacuum evaporation, mild pasteurization, pulsed electric field, and ultra-sonication. Physicochemical properties including Total Soluble Solids (TSS), pH, titratable acidity, and color; Total Phenolic Content (TPC); Total Anthocyanin Content (TAC); antioxidant capacity; and microbiological properties were evaluated. Data were statistically analyzed by Minitab statistical software (version: 18.1).&#x0D; Results: TSS, pH, acidity (%) of processed juices ranged from 11.03-12.03, 4.07-4.27, and 0.42-0.49, respectively. In terms of color properties both ultra-sonication and microwave processing showed the highest values of L (luminosity), a* (redness), and b* (yellow). The highest TPC was reported in ultra-sonication treatment 11.996±0.002 mg Gallic Acid Equivalents (GAE)/100 ml. The TAC varied from 0.179-0.235 mg Total Anthocyanin (TA)/100 ml, where ultra-sonication and mild pasteurization treatment yielded the highest and lowest contents, respectively.&#x0D; Conclusion: Perfect phenolic content, antioxidant capacity, retention of anthocyanin content, and attractive color in pineapple juices when treated with non-thermal techniques.

Effects of rice vinegar treatment on the antioxidant activities and protein structures of whole egg liquid before and after gastrointestinal digestion

In this study, the effects of vinegar treatment on the antioxidant and structural properties of whole egg proteins were investigated. The results showed that the degrees of hydrolysis (DH) of vinegar-treated egg liquid (VE) and digested VE (DVE) increased after vinegar addition. A similar trend was also found for the antioxidant activity of DVE but not for that of VE. The sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) results showed that vinegar treatment increased the gastrointestinal hydrolysis of whole egg protein compared with that of digested egg liquid (DEL) protein, which was in agreement with the free amino acid content results. The Fourier transform infrared (FTIR) analysis results indicated that proteins from VE1:3 tended to form β-sheet structures, whereas proteins from DVE1:3 accumulated α-helices and turns. Vinegar treatment has great potential as a nonthermal processing method for promoting gastrointestinal digestion and producing superior antioxidant peptides.