High Hydrostatic Pressure: Influences on Allergenicity, Bioactivities, and Structural and Functional Properties of Proteins from Diverse Food Sources.

High hydrostatic pressure (HHP) has gained prominence in the food processing industry over the last decade. In addition to the effectiveness of microbial and enzymatic inactivation, HHP directly impacts protein structures and properties. Accordingly, this review article aims to consolidate relevant research findings elucidating the effects of HHP on protein structure, allergenicity, bioactivities, and functional properties across diverse protein sources. They encompass cereals, legumes, nuts, meat, poultry products, milk, eggs, seafood, algae, insects, seeds, and vegetables. This review provides insights into the consistent trends of HHP effects on each protein source. In conclusion, HHP induces alterations in non-covalent bonds within protein structures, leading to the unfolding of their interior regions and consequential changes in their properties. Remarkably, the allergenicity of cereals, legumes, and nuts decreases while their bioactivities and digestibility escalate. The disruption of non-covalent bonds during HHP results in the exposure of the interior hydrophobic regions to the surface microenvironment, thereby enhancing the surface hydrophobicity of proteins, particularly those derived from seeds and vegetables. HHP weakens the allergenicity and elevates the foaming properties of proteins from dairy products, including improving the gelling properties and antioxidant activities of egg proteins. Texture profiles of meat and poultry, particularly hardness, are enhanced. Furthermore, HHP demonstrates the potential to diminish the allergenicity of seafood proteins and augment insect protein bioactivities. Lastly, HHP enhances the extraction of algal bioactive components, improving their nutritional quality.

Extraction, Enzymatic Modification, and Anti-Cancer Potential of an Alternative Plant-Based Protein from Wolffia globosa.

The global plant-based protein demand is rapidly expanding in line with the increase in the world's population. In this study, ultrasonic-assisted extraction (UAE) was applied to extract protein from Wolffia globosa as an alternative source. Enzymatic hydrolysis was used to modify the protein properties for extended use as a functional ingredient. The successful optimal conditions for protein extraction included a liquid to solid ratio of 30 mL/g, 25 min of extraction time, and a 78% sonication amplitude, providing a higher protein extraction yield than alkaline extraction by about 2.17-fold. The derived protein was rich in essential amino acids, including leucine, valine, and phenylalanine. Protamex and Alcalase were used to prepare protein hydrolysates with different degrees of hydrolysis, producing protein fragments with molecular weights ranging between <10 and 61.5 kDa. Enzymatic hydrolysis caused the secondary structural transformations of proteins from ß-sheets and random coils to α-helix and ß-turn structures. Moreover, it influenced the protein functional properties, particularly enhancing the protein solubility and emulsifying activity. Partial hydrolysis (DH3%) improved the foaming properties of proteins; meanwhile, an excess hydrolysis degree reduced the emulsifying stability and oil-binding capacity. The produced protein hydrolysates showed potential as anti-cancer peptides on human ovarian cancer cell lines.

Optimization of enzymatic hydrolysis by alcalase and flavourzyme to enhance the antioxidant properties of jasmine rice bran protein hydrolysate.

This study aimed to optimize the hydrolysis conditions for producing jasmine rice bran protein hydrolysate (JBH) using response surface methodology (RSM). The independent variables were the ratio of flavourzyme to alcalase (Fl:Al; 0: 100 to 15: 85; 2.84% enzyme concentration) and hydrolysis time (60-540 min). The optimum hydrolysate was obtained at an Fl:Al ratio of 9.81: 90.19 for 60 min, since it enabled high amounts of protein, high antioxidant activity and more low molecular weight proteins. The experimental values obtained were a degree of hydrolysis (DH) of 7.18%, a protein content of 41.73%, an IC50 for DPPH of 6.59 mg/mL, an IC50 for ABTS of 0.99 mg/mL, FRAP of 724.81 mmol FeSO4/100 g, and 322.35 and 479.05 mAU*s for peptides with a molecular weight of < 3 and 3-5 kDa, respectively. Using a mixture of enzymes revealed the potential of mixed enzymes to produce JBH containing more small peptides and high antioxidant activity.

On-package indicator films based on natural pigments and polysaccharides for monitoring food quality: a review.

Deterioration of food quality and freshness is mainly due to microbial growth and enzyme activity. Chilled fresh food, especially meat and seafood, as well as pasteurized products, rapidly lose quality and freshness during packing, distribution and storage. Real-time food quality monitoring using on-package indicator films can help consumers make informed purchasing decisions. Interest in the use of intelligent packaging systems for monitoring safety and food quality has increased in recent years. Polysaccharide-based films can be developed into on-package indicator films due to their excellent film-forming properties and biodegradability. Another important component is the use of colorants with visible color changes at various pH levels. Currently, natural pigments are receiving increased attention because of their safety and environmental friendliness. This review highlights the recent findings regarding the role of natural pigments, the effects of incorporating natural pigments and polysaccharides on properties of indicator film, current application and limitations of on-package indicator films based on polysaccharides in some foods, problems and improvement of physical properties and color conversion of indicator film containing natural pigments, and development of polysaccharide-based pH-responsive films. © 2022 Society of Chemical Industry.

Microwave-assisted enzymatic hydrolysis to produce xylooligosaccharides from rice husk alkali-soluble arabinoxylan.

The prebiotic properties of xylooligosaccharides (XOS) and arabino-xylooligosaccharides (AXOS) produced from rice husk (RH) using microwave treatment combined with enzymatic hydrolysis were evaluated. The RH was subjected to microwave pretreatment at 140, 160 and 180 °C for 5, 10 and 15 min to obtain crude arabinoxylan (AX). Increasing microwave pretreatment time increased sugar content. Crude AX was extracted with 2% (w/v) sodium hydroxide at 25 °C for 24 h and used as a substrate for XOS production by commercial xylanases. Results showed that oligosaccharides produced by Pentopan Mono BG and Ultraflo Max provided xylobiose and xylotriose as the main products. AXOS was also present in the oligosaccharides that promoted growth of Lactobacillus spp. and resisted degradation by over 70% after exposure to simulated human digestion.

Properties and kinetics of the in vitro release of anthocyanin-rich microcapsules produced through spray and freeze-drying complex coacervated double emulsions.

This study aimed to prepare anthocyanin-rich microcapsules by spray and freeze-drying complex coacervated double emulsion using gelatin-acacia gum (GE-AG) and chitosan-carboxymethylcellulose (CS-CMC) and to investigate their properties and in vitro release kinetics. Microencapsulation efficiency (MEE) of the microcapsules varied from 84.9% to 94.7%. CS-CMS microcapsules showed significantly higher MEEs than those of GE-AG microcapsules. A significant higher MEE and lower moisture content and hygroscopicity was observed in spray-dried double emulsion (SDE) microcapsules. Freeze-dried double emulsion (FDE) microcapsules possessed higher total anthocyanin and total phenolic contents. The best fit for release kinetics was achieved using first-order and Higuchi models for SDE and FDE microcapsules, respectively. Diffusion-controlled release in the simulated gastric fluid was found for SDE microcapsules, while erosion-controlled release in simulated gastric and intestinal fluids predominated for FDE microcapsules. These findings suggest that the microcapsules can be applied for loading anthocyanins as a nutraceutical with controllable release requirement.

Properties of Peanut (KAC431) Protein Hydrolysates and Their Impact on the Quality of Gluten-Free Rice Bread.

Protein hydrolysates (PH) with a degree of hydrolysis (DH) of 5%, 10%, and 13% from two varieties of peanut were prepared using two commercial enzymes, Alcalase and Flavourzyme. The content of essential amino acids (30,290 mg/100 g) and hydrophobic amino acids (34,067 mg/100 g) of the peanut variety Kalasin 2 (KAC431) protein was higher than that of a common variety, Kalasin 1 (KAC1) (p < 0.05). The protein molecular weight distributions of the two varieties of peanut detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were similar, ranging from 15 to 75 kDa, with a major protein band at 50-75 kDa. The antioxidant and functional properties of derived PHs were influenced by DH. Although the foaming ability of protein was improved by DH5%, it was obviously decreased upon increasing DH further. The best emulsifying properties were observed in PH with DH5% (p < 0.05). The incorporation of PH with a small DH, especially when produced using Flavourzyme, had a highly positive impact on the specific volume and relative elasticity of gluten-free bread. The effect of PHs on bread quality was highly correlated with their functional properties. This study suggests that partially enzymatically modified proteins are suitable for incorporation in food products such as bread and other gluten-free products.

Optimization of simultaneously enzymatic fructo- and inulo-oligosaccharide production using co-substrates of sucrose and inulin from Jerusalem artichoke.

Prebiotic substances are extracted from various plant materials or enzymatic hydrolysis of different substrates. The production of fructo-oligosaccharide (FOS) and inulo-oligosaccharide (IOS) was performed by applying two substrates, sucrose and inulin; oligosaccharide yields were maximized using central composite design to evaluate the parameters influencing oligosaccharide production. Inulin from Jerusalem artichoke (5-15% w/v), sucrose (50-70% w/v), and inulinase from Aspergillus niger (2-7 U/g) were used as variable parameters for optimization. Based on our results, the application of sucrose and inulin as co-substrates for oligosaccharide production through inulinase hydrolysis and synthesis is viable in comparative to a method using a single substrate. Maximum yields (674.82 mg/g substrate) were obtained with 5.95% of inulin, 59.87% of sucrose, and 5.68 U/g of inulinase, with an incubation period of 9 hr. The use of sucrose and inulin as co-substrates in the reaction simultaneously produced FOS and IOS from sucrose and inulin. Total conversion yield was approximately 67%. Our results support the high value-added production of oligosaccharides using Jerusalem artichoke, which is generally used as a substrate in prebiotics and/or bioethanol production.

Antioxidants and antioxidant activity of several pigmented rice brans.

This study investigated the antioxidant content and activity of phenolic acids, anthocyanins, α-tocopherol and γ-oryzanol in pigmented rice (black and red rice) brans. After methanolic extraction, the DPPH free radical scavenging activity and antioxidant activity were measured. The pigmented rice bran extract had a greater reducing power than a normal rice bran extract from a long grain white rice. All bran extracts were highly effective in inhibiting linoleic acid peroxidation (60-85%). High-performance liquid chromatography (HPLC) analysis of antioxidants in rice bran found that γ-oryzanol (39-63%) and phenolic acids (33-43%) were the major antioxidants in all bran samples, and black rice bran also contained anthocyanins 18-26%. HPLC analysis of anthocyanins showed that pigmented bran was rich in cyanidin-3-glucoside (58-95%). Ferulic acid was the dominant phenolic acid in the rice bran samples. Black rice bran contained gallic, hydroxybenzoic, and protocatechuic acids in higher contents than red rice bran and normal rice bran. Furthermore, the addition of 5% black rice bran to wheat flour used for making bread produced a marked increase in the free radical scavenging and antioxidant activity compared to a control bread.