Physicochemical and thermal characteristics of choline chloride-based deep eutectic solvents.

It is essential to investigate the physicochemical and thermal properties of choline chloride (ChCl)-based deep eutectic solvents (DESs) as hydrogen bond acceptor (HBA) with various hydrogen bond donor (HBD) functional groups, such as α-hydroxy acid (lactic acid) or polyol (glycerol). It is important to consider how molar ratios impact these properties, as they may be altered for particular applications. This study aimed to examine the physicochemical and thermal properties of ChCl-based DESs with lactic acid (LA) or glycerol (Gly) at different molar ratios (1:2-1:10). The pH of ChCl:LA (0-1.0) is lower than that of ChCl:Gly (4.0-5.0) because of the hydrogen bonds between ChCl and LA. A higher amount of LA/Gly resulted in higher densities of ChCl:Gly (1.20-1.22 g cm-3) and ChCl:LA (1.16-1.19 g cm-3) due to the stronger hydrogen bonds and tighter packing of the molecules. The refractive index of ChCl:Gly (1.47-1.48) was higher than ChCl:LA (1.44-1.46), with a trend similar to density. The viscosities of ChCl:Gly (0.235-0.453 Pa s) and ChCl:LA (0.04-0.06 Pa s) increased with increasing LA/Gly molar ratio but decreased with temperature due to the high kinetic energy from heating, lowering the attractive forces between molecules. The activation energy for ChCl:LA (15.29-15.55 kJ mol-1) is greater than for ChCl:Gly (7.77-8.78 kJ mol-1), indicating that ChCl:LA has a greater viscosity-temperature dependence than ChCl:Gly. The DESs decomposition temperatures are 179.73-192.14 °C for ChCl:LA and 189.69-197.41 °C for ChCl:Gly. Freezing temperatures are correlated with the molecular weight of HBDs, with lower values causing a larger decrease in freezing temperatures. The interactions of polyols with anions were stronger than those of α-hydroxy acids with anions. The variations in HBA to HBD molar ratios affected DESs properties, providing a fundamental understanding of the properties critical for their diverse applications.

Comparative Study of The Yield and Physicochemical Properties of Collagen from Sea Cucumber (Holothuria scabra), Obtained through Dialysis and the Ultrafiltration Membrane.

Collagen was extracted from the body wall of sea cucumber (Holothuria scabra) using the pepsin-solubilized collagen method followed by isolation using dialysis and the ultrafiltration membrane. The yield and physicochemical properties of the collagen obtained from both isolation methods, denoted as D-PSC and UF-PSC, were compared. The ultrafiltration method affords a higher yield of collagen (11.39%) than that of the dialysis (5.15%). The isolated collagens have almost the same amino acid composition, while their functional groups, referred to as amide A, B, I, II, and III bands, were in accordance with commercial collagen, as verified by Fourier Transform Infrared (FT-IR) spectroscopy. The UV-Vis absorption peaks at 240 nm and 220 nm, respectively, indicated that the collagens produced are type-I collagen. The D-PSC showed interconnecting sheet-like fibrils, while the UF-PSC exhibited a flaky structure with flat-sheets arranged very close to each other. The higher yield and comparable physicochemical properties of the collagen obtained by ultrafiltration as compared with dialysis indicate that the membrane process has high potential to be used in large-scale collagen production for food and pharmaceutical applications.

The effect of frying on browning, acrylamide and 5-hydroxymethylfurfural formation on Malaysian curry puff skin treated with l-asparaginase.

Acrylamide and 5-hydroxymethylfurfural (HMF) is the product of the Maillard reaction and its accumulation may lead to adverse health effects. Hence, this paper aims to study the effect of l-asparaginase treatment (E100 U/kg and E500 U/kg), frying temperatures (180 °C, 190 °C, 200 °C) and times (2 min, 3 min, 5 min, 7 min) on acrylamide and HMF content after the frying process of curry puff skin. Colour development, moisture content, water activity analysis and sensory evaluation were also carried out. Frying condition at 190 °C for 5 min produced desirable attributes through sensory evaluation. Furthermore, the enzyme reduced the acrylamide and HMF level to 2500 µg/kg and 230 µg/kg respectively. Frying temperature plays a crucial role in acrylamide decomposition leading to the reduction of acrylamide content. Therefore, the use of this enzyme is plausible for the reduction of acrylamide and HMF in puff skin without altering the original quality.

Gelatine Film Incorporated with Clitoria ternatea-Derived Anthocyanin Microcapsules, A Food Packaging Material Effective Against Foodborne Pathogens.

RESEARCH BACKGROUND: Microbial contamination of food products is one of the significant causes of food spoilage and foodborne illnesses. The use of active packaging films incorporated with antimicrobial agents can be a measure to improve food quality and extend shelf life. Nevertheless, antimicrobial agents such as silver, copper, titanium and zinc in the packaging films have raised concerns among consumers due to toxicity issues. EXPERIMENTAL APPROACH: The current study aims to develop biodegradable gelatine-based edible films incorporated with microcapsules of Clitoria ternatea-derived anthocyanins as a natural antimicrobial agent. The impact of incorporation of microcapsules with anthocyanins on the morphology, thermal, mechanical, water vapour barrier and physicochemical properties of the gelatine films was evaluated in this study. The effectiveness of the developed films against foodborne pathogens and their application for perishable food protection were also investigated. RESULTS AND CONCLUSIONS: The results show that incorporating anthocyanin microcapsules enhances the gelatine film physical and mechanical properties by increasing the thickness, tensile strength, Young's modulus and elongation at break of the films. Scanning electronic microscopy analysis revealed that the film surface morphology with anthocyanin microcapsules had a homogeneous and smooth surface texture compared to the control. The thermogravimetric analysis also showed a slight improvement in the thermal properties of the developed films. Agar well diffusion assay revealed that the developed films exhibit significant inhibition against a broad-spectrum of bacteria. Furthermore, the films composed of gelatine with anthocyanin microcapsules significantly reduced the total viable count of microorganisms in the bean curd during storage for 12 days compared with the control films. NOVELTY AND SCIENTIFIC CONTRIBUTION: Increasing global awareness of healthy and safe food with minimal synthetic ingredients as preservatives has sparked the search for the use of antimicrobial agents of natural origins in active food packaging material. In this study, a safe and effective active packaging film was developed using an environmentally friendly biopolymer, gelatine film incorporated with microcapsules of Clitoria ternatea-derived anthocyanins as a natural antimicrobial agent. This study demonstrated that such a method is not only able to improve the film physical properties but can also significantly prolong the shelf life of food products by protecting them from microbial spoilage.

Prebiotics metabolism by gut-isolated probiotics.

There are numerous species of bacteria resides in the lumen of human colon. The word 'colon', resembles colony or the colonization of microbiota of which plays an important role in the fermentation of prebiotics. The standpoint of prebiotic nowadays is well reported for attenuating gut dysbiosis in many clinical studies tested on animals and human. However, because of the huge amount of gut microbiome, the attempt to connect the dots between bacterial population and the host are not plainly discernible. Thus, a need to analyse recent research on the pathways of prebiotic metabolism adopted by commonly studied probiotics i.e. Bifidobacteria and Lactobacillus. Several different substrate-dependent gene expressions are induced to break down oligosaccharide molecules shown by those probiotics. The hydrolysis can occur either by membrane bound (extracellular) or cytoplasmic (intracellular) enzyme of the enteric bacteria. Therefore, this review narrates several prebiotic metabolisms occur during gut fermentation, and metabolite production i.e. organic acids conversion.