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.

Isolation and Identification of Antioxidant Peptides Derived from Cricket (Gryllus bimaculatus) Protein Fractions.

Crickets contain high protein content that can be used to improve nutrition but are less exploited. This study was conducted to isolate different Cricket Protein Fractions including albumin, globulin, glutelin, and prolamin. All fractions were characterized and hydrolyzed by commercial enzymes. The results showed that the glutelin fractions had the highest extraction yields with 53.9 ± 2.12% (p < 0.05). Moreover, glutelin hydrolysate fraction prepared by Alcalase with a 16.35 ±0.29% hydrolysis degree was selected for further purification because of their high antioxidant activities, including ABTS radical-scavenging activity (0.44-0.55 µmol Trolox eq./g) and metal chelating activity (1721.99-1751.71 µmol EDTA eq./g). Two active fractions, GA-1 (<3 kDa) and GA-2 (<3 kDa), were collected from the consecutive purification of glutelin hydrolysates, which included processes such as membrane ultrafiltration and gel filtration. The fractions were analyzed by LC-MS/MS to obtain 10 peptides with 3-13 amino acids identified as TEAPLNPK, EVGA, KLL, TGNLPGAAHPLLL, AHLLT, LSPLYE, AGVL, VAAV, VAGL, and QLL with a molecular weight range of 359.23-721.37 Da in the two fractions. The amino acid sequence shows a prevalence of hydrophobic amino acids (50-100%) such as valine and leucine in the peptide chains, accounting for its high antioxidant activity. In conclusion, cricket glutelin hydrolysate prepared by Alcalase can serve as an alternative source of potent edible bioactive peptides in functional food products.

Impacts of Electroextraction Using the Pulsed Electric Field on Properties of Rice Bran Protein.

The pulsed electric field (PEF) was applied to improve the extraction yield and properties of rice bran proteins from two rice varieties ("Kum Chao Mor Chor 107" and "Kum Doi Saket"). As compared to the conventional alkaline extraction, PEF treatment at 2.3 kV for 25 min increased the protein extraction efficiency by 20.71-22.8% (p < 0.05). The molecular weight distribution detected by SDS-PAGE and amino acid profiles of extracted rice bran proteins was likely unchanged. The PEF treatment influenced changes in the secondary structures of rice bran proteins, especially from the ß-turn to the ß-sheet structure. Functional properties of rice bran protein including oil holding capacity and emulsifying properties were significantly improved by PEF treatments by about 20.29-22.64% and 3.3-12.0% (p < 0.05), respectively. Foaming ability and foam stability increased by 1.8- to 2.9-fold. Moreover, the in vitro digestibility of protein was also enhanced, which was consistent with the increment of DPPH and ABTS radical-scavenging activities of peptides generated under in vitro gastrointestinal digestion (37.84-40.45% and 28.46-37.86%, respectively). In conclusion, the PEF process could be a novel technique for assisting the extraction and modification of the protein's digestibility and functional properties.

Mango Pectic Oligosaccharides: A Novel Prebiotic for Functional Food.

Prebiotics are functional food ingredients that assist probiotic growth and render many other health benefits. Mango peel is the biomass of the processing industry and has recently been value-added as a dietary fiber pectin. Besides its general use as a food additive, mango peel pectin (MPP) is partially hydrolyzed by pectinase to obtain pectic oligosaccharides (POSs) that have recently gained attention as novel prebiotic products and in medical research. This review describes probiotic candidates responsible for the digestion of pectin derivatives and the advantages of POSs as functional additives and their current best retrieval options. Mango pectic oligosaccharide (MPOS) recovery from low methoxyl MPP from mango with prebiotic performance both in vivo and in vitro environments is discussed. Current research gaps and potential developments in the field are also explored. The overall worthiness of this article is the potential use of the cheap-green food processing bioresource for high-value components.

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.

Selenium-enriched plant foods: Selenium accumulation, speciation, and health functionality.

Selenium (Se) is an essential element for maintaining human health. The biological effects and toxicity of Se compounds in humans are related to their chemical forms and consumption doses. In general, organic Se species, including selenoamino acids such as selenomethionine (SeMet), selenocystine (SeCys2), and Se-methylselenocysteine (MSC), could provide greater bioactivities with less toxicity compared to those inorganics including selenite (Se IV) and selenate (Se VI). Plants are vital sources of organic Se because they can accumulate inorganic Se or metabolites and store them as organic Se forms. Therefore, Se-enriched plants could be applied as human food to reduce deficiency problems and deliver health benefits. This review describes the recent studies on the enrichment of Se-containing plants in particular Se accumulation and speciation, their functional properties related to human health, and future perspectives for developing Se-enriched foods. Generally, Se's concentration and chemical forms in plants are determined by the accumulation ability of plant species. Brassica family and cereal grains have excessive accumulation capacity and store major organic Se compounds in their cells compared to other plants. The biological properties of Se-enriched plants, including antioxidant, anti-diabetes, and anticancer activities, have significantly presented in both in vitro cell culture models and in vivo animal assays. Comparatively, fewer human clinical trials are available. Scientific investigations on the functional health properties of Se-enriched edible plants in humans are essential to achieve in-depth information supporting the value of Se-enriched food to humans.

Microencapsulation of Cyclocarya paliurus (Batal.) Iljinskaja Extracts: A Promising Technique to Protect Phenolic Compounds and Antioxidant Capacities.

This study aimed to protect phenolic compounds of Cyclocarya paliurus (Batal.) Iljinskaja (C. paliurus) using a microencapsulation technique. Ethanol and aqueous extracts were prepared from C. paliurus leaves and microencapsulated via microfluidic-jet spray drying using three types of wall material: (1) maltodextrin (MD; 10-13, DE) alone; (2) MD:gum acacia (GA) of 1:1 ratio; (3) MD:GA of 1:3 ratio. The powders' physicochemical properties, microstructure, and phenolic profiles were investigated, emphasizing the retentions of the total and individual phenolic compounds and their antioxidant capacities (AOC) after spray drying. Results showed that all powders had good physical properties, including high solubilities (88.81 to 99.12%), low moisture contents (4.09 to 6.64%) and low water activities (0.11 to 0.19). The extract type used for encapsulation was significantly (p < 0.05) influenced the powder color, and more importantly the retention of total phenolic compounds (TPC) and AOC. Overall, the ethanol extract powders showed higher TPC and AOC values (50.93-63.94 mg gallic acid equivalents/g and 444.63-513.49 µM TE/g, respectively), while powders derived from the aqueous extract exhibited superior solubility, attractive color, and good retention of individual phenolic compounds after spray drying. The high-quality powders obtained in the current study will bring opportunities for use in functional food products with potential health benefits.

Comparing Three Types of Mandarin Powders Prepared via Microfluidic-Jet Spray Drying: Physical Properties, Phenolic Retention and Volatile Profiling.

This study aimed to offer an alternative way for delivering the benefits of the mandarin fruit juice to consumers via spray drying microencapsulation. Two mandarin cultivars, Afourer (A) and Richard Special (RS), were studied. Three types of juice sample were prepared, i.e., the whole fruit juice (A3 & RS3), the flavedo-removed fruit juice (A2 & RS2), and the peel-removed fruit juice (A1 & RS1) samples. Gum Acacia and maltodextrin (ratio of 1:1, w/w) were chosen as wall matrices for aiding the drying of the juice samples while using a microfluidic-jet spray dryer. The properties of the fruit powder (colour, water activity, bulk/trapped density, solubility, hygroscopicity, morphology) and the retention of major phytochemicals (i.e., phenolic and volatile compounds) were examined. The results showed that the powders produced from the whole fruit juices (A3 and RS3) gave higher yellow colour with a regular winkled surface than other powders (A1 & RS1, and A2 & RS2). The water activity of mandarin powders was in a range of 0.14 to 0.25, and the solubility was around 74% with no significant difference among all of the powders. The whole fruit powders had a significantly higher concentration of phenolic compounds (A3, 1023 µg/100 mg vs. A2, 809 µg/100 mg vs. A1, 653 µg/100 mg) and aroma compounds (A3, 775,558 µg/L vs. A2, 125,617 µg/L vs. A1, 12,590 µg/L). This study contributed to the delivery of phenolic and flavour compounds of the mandarin fruits, at the same time minimising waste generation during processing. It also gave insight into the production of spray-dried powders from the whole mandarin fruits.