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The incidence of food allergy has been increasing in recent years, but the prevention, diagnosis, and treatment of food allergy remain challenges in the world. Food allergen epitope mapping technology can help us identify the epitope sequence and structure, which is conducive to the development of food allergy prevention, diagnosis, and treatment methods. Moreover, the information about allergic epitopes also plays a positive role in the development of new hypoallergenic or non-allergenic food products in the industry. This article systematically reviews state-of-art research progress and development trend of food epitope mapping technology based on the advantages and disadvantages as well as the potentials of each method. The future development direction and trend of food protein allergen epitope mapping technology were also discussed, with a view to providing a reference for the identification and characterization of food allergens. Compared with traditional technologies including peptide scanning technique, novel technologies have the advantages of high specificity, high sensitivity, high accuracy, and high-throughput. Although some progress has been made in the identification and characterization of food protein allergen epitopes, a large number of epitopes have not yet been identified so far. Some work is still needed for invention of new epitope mapping technology, establishment of systematic and comprehensive databases, and development of allergic omics in the future. • Specificity between IgE antibodies and epitopes is indicator of food allergy. • Recent advances in techniques have enabled efficient prediction of epitopes. • Current and development of food epitope mapping technologies were discussed. • Epitope identification mechanism would be better understood. • Diagnosis/prognosis of food protein allergies would be more effectively. [ABSTRACT FROM AUTHOR]

The mild alkali extraction combined with the enzymatic hydrolysis was explored to extract protein from glutinous rice bran in the study, and the function properties of the proteins were investigated. The mild alkali extraction of pH 5.0 and temperature 50°C was carried out firstly for the water‐soluble protein extraction from the bran at the solid–liquid ratio of 1:10 (w/v) for 3.0 h, and the complex enzyme of cellulase and papain (7:3, w/w) were subsequently added to hydrolyze the residue for a better protein yield. After a mild proteolysis treatment under the conditions of enzyme addition 5.0%, pH 6.0, temperature 55°C and time 4.5 h, the final 90.2 ± 0.22% protein yield was obtained. It was interesting that the DPPH radical scavenging activity of the IC50 0.71 mg/ml was significantly improved, meanwhile, based on the combined extraction strategy, the protein solubility, emulsifying, and foaming properties were significantly enhanced in a wide range of pH environments. These results demonstrated that the mild alkali extraction combined with the enzymatic hydrolysis could be used in the glutinous rice bran protein extraction with high yield and good functionality, and the extracted protein could be potentially applied in food industry as nutraceutical ingredient or as the functional ingredient in the commercialized food products. Novelty impact statement: Although the glutinous rice bran has an abundance of protein content, the protein has not been well extracted yet to be utilized in the food industry. Therefore, the proper procedure needs to be explored for glutinous rice bran protein extraction. The mild alkali combined with the enzymatic hydrolysis was firstly applied in the study, and the protein yield of glutinous rice bran protein was notably improved, furthermore, the antioxidant and function properties of glutinous rice bran protein also have been significantly increased because of the mild extraction and proteolysis. [ABSTRACT FROM AUTHOR]

A simple and efficient method to extract and purify anthocyanins from black rice was developed in this work. After pretreatment of black rice, anthocyanins were extracted by buffer solutions, and were purified using membrane separation and resin adsorption. The single-factor experiments and orthogonal design were applied. The results showed that extraction ratio could be 0.99 ± 0.01% under the optimal condition of liquid-solid ratio 12:1, temperature 50C, time 80 min and pH 3.2. The 3 kDa molecular weight cut-off (MWCO) was used to remove proteins and polysaccharides, and the DM301 resin was found to have both good adsorptivity and desorptivity for anthocyanins. After the elution using 85% (vol/vol) ethanol solution, the purified anthocyanins were obtained by retention with the membrane of 200 Da MWCO. The recovery and purity of the anthocyanins finally obtained was 0.86% and 95.93%, respectively. The results are beneficial to the large-scale extraction of anthocyanins from black rice. Practical Applications Due to the growing demand for natural pigments, the natural anthocyanins have drawn great attentions. However, the immaturity of the large-scale purification procedures has limited the application of anthocyanins in functional food and pharmaceutical industries. Since the black rice is the rich source of anthocyanins, the large-scale water extraction and macroporous absorbent resins purification parameters were systematically investigated in the current study. About 0.86 g anthocyanins could be obtained from per 100 g black rice based on the large-scale method, which has a good recovery, and the purity could reach 95.93%. Meanwhile, the whole procedure was green and non-pollution as the primary solvents were water and ethanol. Furthermore, the results also would be conducive to the processing and utilization of black rice. [ABSTRACT FROM AUTHOR]

• Low pH-shifting was used in black turtle bean protein isolate treatment. • Protein isolates were adjusted to neutral from pH 3.0, 2.0, 1.5, 1.0 incubations. • Protein was unfolded with exposure of buried hydrophobic residues after treatment. • Hydrophobic functionalities were improved, with decrease of hydrophilic properties. • Lower hemagglutination and immunoreactivity were obtained with better digestibility. Low pH-shifting was firstly applied in the black turtle bean (Phaseolus vulgaris L.) protein isolate treatment by acidic (pH 1.0–3.0) buffer incubation for 8 h, then was adjusted to pH 7.2 and kept 3 h for protein stabilizing. Mild loss of secondary structure was confirmed in the protein isolate after low pH-shifting treatment by CD and FT-IR analyses. Intrinsic fluorescence, UV spectra, surface hydrophobicity, SH content and SDS-PAGE analyses indicated the protein conformation was unfolded with the exposure of much more buried hydrophobic residues, which would result in the enhancement of emulsifying properties, foaming properties and fat holding capacity, and lead to the reduction of solubility and water holding capacity. Furthermore, lower immunoreactivity was observed by the ELISA, and improved digestibility was found in in vitro digestion assay. Our results suggested the low pH-shifting treatments would broaden the application of bean protein isolate with better hydrophobic processing functions and safety. [ABSTRACT FROM AUTHOR]

• Protein extracted at pH 9.0 had lower glucosinolates, phytic acid and sinapine. • Protein extracted at pH 9.0 had lighter colour and lower D-amino acid content. • Protein obtained at pH 4.5 had the lowest glucosinolates, phytic acid and sinapine. • Water/oil absorption, foaming and emulsifying features decreased as pH decreased. • The α-polypeptide of cruciferin and napin showed gastric digestive resistance. Cold-pressed rapeseed meal with high protein content (38.76% protein dry weight basis) was used to prepare rapeseed protein isolates (RPIs) by alkaline extraction (pH 8.0, 9.0, 10.0, 11.0, 12.0 and 13.0) and acid precipitation (pH 3.0, 3.5, 4.0, 4.5, 5.0 and 5.5). The protein with an intact structure and the highest yield (65.08%) was obtained at extraction pH 9.0 and precipitation pH 4.5, accompanied by the lowest D-amino acid content, the lightest colour and the lowest contents of glucosinolates (2.85 mmol/kg), phytic acid (1.05 mg/g) and sinapine (0.68 mg/g). Additionally, water/oil absorption, foaming and emulsifying capacities decreased with decreasing precipitation pH, while the solubility showed the reverse trend. During gastric simulation digestion, the α-polypeptide of cruciferin and napin in the RPIs showed digestive resistance. Overall, pH regulation might be an effective method to isolate high quality RPIs for use in the food processing industry. [ABSTRACT FROM AUTHOR]