Potential of whey protein isolate-lactose conjugates in the in-vitro infant digestion

Protein base modification is a notable potential method to alter the molecular structure and physicochemical and functional properties of the protein, thus affecting protein digestibility. This study investigated the protein digestibility of whey protein isolate– lactose (WPI-Lac) conjugates using an in-vitro infant gastric digestion static model. WPI was conjugated with lactose by dry Maillard reaction under optimised conditions. The following conditions were studied, WPI-Lac heated at 40°C, water activity aw = 0.80 and incubation time of 0, 1, 3, 5 and 7 days. Based on the brown colour and the conjugation rates in ortho-phthaldehyde analysis, the incubation time of day 3 of conjugation promises the extent of conjugation and prevents the formation of advanced Maillard reaction products (MRPs). Functional properties of glycated protein were found to significantly higher (p&lt;0.05) in antioxidant activity and solubility compared with native WPI. In addition, Fourier Transform Infrared (FTIR) analysis indicated that the WPI was modified by dry MR with lactose. WPI-Lac day 3 was evaluated using the in-vitro gastric infant digestion model which undergo simulated gastric infant condition at pH 3 with 19 µL of 0.625mg/mL of pepsin. Sodium dodecyl sulfate acrylamide gel electrophoresis (SDSPAGE) analysis of digesta revealed that MRPs increased susceptibility to be hydrolysed by pepsin. The digestion product affirms dry MR conjugation can potentially improve WPI digestibility. Herein, this study of WPI-Lac conjugates contributes to an understanding of how protein–disaccharide glycates affect in-vitro infant gastric digestion.</jats:p

Chemical composition of the fillet, fins, bones and viscera of hybrid grouper (Epinephelus lanceolatus x Epinephelus fuscoguttatus)

Abstract Fish provides a rich source of protein, fatty acids and minerals. Being the world’s first hybridised grouper (TGGG) as a result of cross-breeding the giant grouper and tiger grouper, TGGG has proven to be more disease-resistant as compared to both of its parent species. It is important to determine the nutrients compositions of all parts of the fish as a means of widening its scope of usage. The objective of this study is to determine the chemical compositions from the fillet, fins, bones and viscera of TGGG. The results showed that the fins and fillet contained high levels of protein (fins: 68.12%; fillet: 78.63%) and low Na/K ratios (fins: 0.4; fillet: 0.1). Essential amino acids (EAA) in the fillet were comparable to FAO/WHO requirements. The lipid from viscera contained SFA as the major component, whereas other fish parts were rich in unsaturated FA. Both the fillet and fins had the same PUFA/SFA ratio (0.43) and was higher than bones (0.31) and viscera (0.25). Glycine and proline were the most abundant AA, while calcium was the major mineral in the bones. In summary, each part of the fish could be potential new sources of specific nutrient components.</jats:p

In Vitro Digestibility and Thermal Properties of Native and Modified Sago (Metroxylon Sagu) Starch

Abstract In recent years, there is growing interest in the nutritional implications of resistant starch in foods due to its functional properties and health benefits. This has resulted to the development of various modification techniques to induce the formation of resistant starch. This study aimed to elucidate the effect of different modifications on digestibility and thermal properties of sago starch. Sago starch was treated with hydrothermal treatment [heat moisture treatment (HMT) and annealing (ANN)] as well as combined modification of acid methanol treatment (AMT) and hydrothermal treatment (HMT and ANN), respectively. Combined modification (AMT-HMT and AMT-ANN) had more pronounced effect in increasing the resistant starch (RS) content and lowering the glycemic index (GI) of sago starch, especially in gelatinized form. Strong negative correlation was obtained between RS and GI in both raw and gelatinised starch. Combination of acid methanol treatment with annealing caused the highest increment in gelatinization temperatures of sago starch.</jats:p

Characteristics of rambutan (Nephelium lappaceum L.) seed fat fractions and their potential application as cocoa butter improver

The utilization of rambutan seed (Nephelium Lappaceum L.) to produce fat (RSF) and its fractionation could be one of the solutions for better waste management and for ensuring its sustainable utilization. In this study, RSF was fractionated by two-stage acetone fractionation and their physicochemical properties such as fatty acid compositions, iodine value (IV), free fatty acid (FFA), slip melting point (SMP), and solid fat content (SFC) were investigated. The solid fraction-III (F2-S) exhibited the highest SMP (49.03°C) and lowest IV (27.57 g I2/100 g). The major fatty acids in all solid fractions were stearic (15.1- 21.6%), oleic (25.0-35.5%), and arachidic (42.7-46.9%) acids. The SFC of F2-S at 20°C (78.57%) and 35°C (22.95%) were found to be higher than solid fraction-I (F1-S), indicating a harder solid fraction. This study revealed that by performing fractionation of RSF, a cocoa butter improvers (CBI) could be prepared by blending them with other fats that have the potential to be utilized in chocolate manufacturing in tropical countries</jats:p