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<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.
In the past few years, researchers have focused on improving the functional properties and qualities of food products. To this end, they have used crosslinking for enhancing the functional properties of proteins in the food products. Enzymatic or non-enzymatic crosslinking can be used to modify food proteins. Protein crosslinking is efficient in generating novel textures and developing product formulations, while also maintaining the desired texture and mouthfeel of food products. Enzymatic treatments using laccases, transglutaminases, peroxidases, and tyrosinases could help in designing meat replacement products, and developing non-dairy yoghurt and cheeses with good consistency. However, these catalytic mechanisms are accompanied by many technical issues that need to be overcome while developing complex food matrices.
The aim of the present work was to investigate the spray-dried characteristics such as physical properties, morphologies, glass transition temperatures (Tg), and prebiotic activity of white dragon fruit (WDF) powders produced using different wall materials, namely resistant maltodextrin (RMD) and maltodextrin (MD), at optimum spray drying conditions. Results showed that RMD decreased water activity and moisture content, and increased bulk density and true density of powder more than MD. In addition, the particle size of RMD-coated powder (WRMD) was smaller than that of MD-coated powder (WMD), and the morphology of the WRMD powder showed that it had a smooth surface as compared to WMD powder, where shrinkage and dent surfaces were observed. The Tg of WMD powder had higher value, but both types of powders were not significantly (p > 0.05) different. Then, both powders were further investigated for their ability to support the growth of Bifidobacterium longum BB536 and Lactobacillus casei Shirota. The growth of the anaerobic bacteria was determined every 6 h for 24 h at 37°C in six modified MRS media containing glucose, RMD, MD, WRMD powder, WMD powder, and fructooligosaccharides (FOS) as the substrates. Results indicated that all substrates significantly (p < 0.05) increased the growth of the probiotic bacteria, with WRMD powder yielding the highest bacterial count. Based on the findings, WRMD powder can be considerably used as a new prebiotic source for the functional food industry.
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
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.
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.
The pre‐treatment of oilseeds prior to extraction process may affect oil yield and quality. The aim of this study was to investigate the effects of two drying methods on rambutan seed fat (RSF) yield and their oxidative stability, physicochemical properties, and crystal morphology. Response surface methodology (RSM) was used in the optimisation and investigation of the effects of three process conditions: seed weight (g), extraction time (min), and solvent volume (ml) on RSF yield. Under optimal conditions, a maximum RSF yield of 44.14% was obtained. The differences between RSF pre‐treated with oven‐drying and RSF with freeze‐drying methods in slip melting point (38.3°C to 39.7°C), free fatty acid (3.13 to 3.50 mg KOH/g fat), peroxide value (1.04 to 1.67 meq of O2/kg of fat), p‐anisidine value (1.10 to 1.56), and total oxidation value (4.21 to 5.67) were significant (p < 0.05). Both fats showed needle‐like shaped crystals. Our results provide useful information in the pre‐treatment of RSF, which has potential to be used as blending component with palm oil for cocoa butter equivalent formulation in chocolate and confectionery industries.
It is crucial to determine several protein-related parameters at the initial stages of proteomic analysis of any biological samples. In this study, crude protein content, total soluble protein, total phenolic content and the SDS-PAGE profile of fifteen varieties of seaweed from Semporna, Sabah, Malaysia were analysed. The crude protein, total soluble protein and total phenolic content of all seaweed samples were in the range of 3.99 to 13.18 % of dry weight, 0.52 to 1.45 mg/mL in acetone dried powder samples and 8.59 to 48.98 mg PGE/g dry weight, respectively. In general, the differences (crude protein, total soluble protein and total phenolic content) among all fifteen varieties of seaweeds were significant (p<0.05). There was also a strong positive correlation between crude protein and total soluble protein concentration (Pearson’s Correlation Coefficient (r)=0.923; p=0.01) in these fifteen varieties of seaweed. A distinctive protein pattern was observed in the SDS-PAGE gels between three different seaweed classes of green, red and brown colours. All of these results are important in sample preparations (extractions) before furthering proteomic analysis in order to identify and characterize seaweed proteomes.
A study was conducted to produce white dragon fruit (WDF) powder by optimizing the spray drying conditions using maltodextrin DE 10 (MD) as a carrier. The process was performed using a pilot plant spray drier by manipulating its inlet temperature (150-170°C), outlet temperature (75-85°C) and MD concentration (15-30%) as the independent variables while process yield, moisture content, water activity, hygroscopicity and bulk density were analysed as responses. The optimum conditions were obtained at an inlet temperature of 150°C, outlet temperature of 75°C and 18% of MD concentration. MD concentration had the most significant (p 0.05) from its initial count in media containing FOS and WDF powder while glucose and MD significantly (p<0.05) increased its numbers. These results indicated that WDF powder enhanced the growth of probiotic bacteria more than FOS and inhibited the growth of pathogen and as such can be considered as a functional food ingredient for the functional food industry.