Influence of Soy Lecithin and Sodium Caseinate on The Stability and in vitro Bioaccessibility of Lycopene Nanodispersion.

Research background: Various approaches have been used to present functional lipids including lycopene in a palatable food form to consumers. However, being highly hydrophobic, lycopene is insoluble in aqueous systems and has a limited bioavailability in the body. Lycopene nanodispersion is expected to improve the properties of lycopene, but its stability and bioaccessibility are also affected by emulsifier type and environmental conditions such as pH, ionic strength and temperature. Experimental approach: The influence of soy lecithin, sodium caseinate and soy lecithin/sodium caseinate at 1:1 ratio on the physicochemical properties and stability of lycopene nanodispersion prepared using the emulsification-evaporation methods before and after treatment at different pH, ionic strength and temperature were investigated. The in vitro bioaccessibility of the nanodispersions was also studied. Results and conclusion: Under neutral pH conditions, nanodispersion stabilized with soy lecithin had the highest physical stability and the smallest particle size (78 nm), the lowest polydispersity index (PDI) value (0.180) and highest zeta potential (-64 mV) but the lowest lycopene concentration (1.826 mg/100 mL). Conversely, nanodispersion stabilized with sodium caseinate had the lowest physical stability. Combining the soy lecithin with sodium caseinate at 1:1 ratio resulted in a physically stable lycopene nanodispersion with the highest lycopene concentration (2.656 mg/100 mL). The lycopene nanodispersion produced by soy lecithin also had high physical stability under different pH range (pH=2-8) where the particle size, PDI and zeta potential remained fairly consistent. The nanodispersion containing sodium caseinate was unstable and droplet aggregation occurred when the pH was reduced close to the isoelectric point of sodium caseinate (pH=4-5). The particle size and PDI value of nanodispersion stabilized with soy lecithin and sodium caseinate mixture increased sharply when the NaCl concentration increased above 100 mM, while the soy lecithin and sodium caseinate counterparts were more stable. All of the nanodispersions showed good stability with respect to temperature changes (30-100 °C) except for the one stabilized by sodium caseinate, which exhibited an increased particle size when heated to above 60 °C. The combination of soy lecithin and sodium caseinate was found to increase the bioaccessibility of the lycopene nanodispersion. The physicochemical properties, stability and extent of the lycopene nanodispersion digestion highly depend on the emulsifier type. Novelty and scientific contribution: Producing a nanodispersion is considered one of the best ways to overcome the poor water solubility, stability and bioavailability issues of lycopene. Currently, studies related to lycopene-fortified delivery systems, particularly in the form of nanodispersion, are still limited. The information obtained on the physicochemical properties, stability and bioaccessibility of lycopene nanodispersion is useful for the development of an effective delivery system for various functional lipids.

Modification methods toward the production of porous starch: a review.

Starch is a complex carbohydrate formed by the repeating units of glucose structure connected by the alpha-glycosidic linkages. Starch is classified according to their derivatives such as cereals, legumes, tubers, palms, fruits, and stems. For decades, native starch has been widely utilized in various applications such as a thickener, stabilizer, binder, and coating agent. However, starches need to be modified to enhance their properties and to make them more functional in a wide range of applications. Porous starch is a modified starch product which has attracted interest of late. It consists of abundant pores that are distributed on the granule surface without compromising the integrity of its granular structure. Porous starch can be produced either by enzymatic, chemical, and physical methods or a combination thereof. The type of starch and selection of the modification method highly influence the formation of pore structure. By carefully choosing a suitable starch and modification method, the desired morphology of porous starch can be produced and applied accordingly for its intended application. Innovations and technologies related to starch modification methods have evolved over the years in terms of the structure, properties and modification effects of different starch varieties. Therefore, this article reviews recent modification methods in developing porous starch from various origins.

Evaluation of probiotic potential and anti-hyperglycemic properties of a novel Lactobacillus strain isolated from water kefir grains.

A total of eight strains of lactic acid bacteria were isolated from water kefir grains and assessed for their in vitro α-glucosidase inhibitory activity. Lactobacillus mali K8 demonstrated significantly higher inhibition as compared to the other strains, thus was selected for in vitro probiotic potential characterization, antibiotic resistance, hemolytic activity and adaptation to pumpkin fruit puree. L. mali K8 demonstrated tolerance to pH 2.5 and resisted the damaging effects of bile salts, pepsin and pancreatin, comparable to that of Lactobacillus rhamnosus GG ATCC 53103 (reference strain). Lack of hemolytic activity and susceptibility to the five standard antibiotics indicated the safety of the K8 strain. This strain showed singular properties to be used as starters in the pumpkin fruit puree fermentation. These preliminary in vitro tests indicated the safety and functionality of the K8 strain and its potential as a probiotic candidate.

Development of a novel fermented pumpkin-based beverage inoculated with water kefir grains: a response surface methodology approach.

Pumpkin (Cucurbita pepo) is well known for its health and nutritional benefits and is recommended for daily consumption. This is the first report on optimization and development of fermented pumpkin-based water kefir beverage. Optimum pumpkin puree and brown sugar concentrations were found at 22.28 and 9.07% w/v, respectively, were made into a pumpkin-based beverage and fermented with water kefir grains for 24 h at 32 °C. The optimized fermented pumpkin-based water kefir beverage was found to be non-alcoholic, achieved good overall acceptability and high Lactobacillus, acetic acid bacteria and yeast cell viability of approximately 1012, 109 and 109 CFU mL-1, respectively. Overall, the optimized product attained superb technological characteristics and has the potential for industrial exploitation as a refreshing water kefir drink.