Ratchadaporn Oonsivilai

Entrapment in food-grade transglutaminase cross-linked gelatin–maltodextrin microspheres protects Lactobacillus spp. during exposure to simulated gastro-intestinal juices

Dietary intake of probiotic bacteria has been shown to impart health effects, however, maintaining viable cells in foods and during passage of the adverse conditions in the upper gastro-intestinal tract is often a problem. The objective of this research was to develop and characterize novel food-grade phase-separated gelatin-maltodextrin (G-MD) microspheres, where the gelatin was cross-linked with transglutaminase (TGase), to determine if encapsulated probiotic lactic acid bacteria were protected during exposure to simulated upper gastro-intestinal tract conditions. The stability, size, structure and protective ability of G-MD microspheres as a function of different TGase concentrations and gelatin bloom strengths were tested. The G-MD microspheres made with gelatin A 300 bloom and a TGase concentration of 10U/g prevented pepsin-induced degradation of the microspheres in simulated gastric juice (pH2.0, 2h, 37°C), resulting in significantly (p<0.05) higher numbers of survivors due to the buffering effect of intact microspheres (average diameter 46μm). After sequential incubation in simulated gastric (1h) and intestinal juices (pH7.4, 4h, 37°C), survivor levels of each of the three encapsulated Lactobacillus sp. (3C2-10, 21C2-10 and 21C2-12) were reduced by 0.2-1log(CFU/g) as compared to 3-4log(CFU/g) for the free non-encapsulated cells. This study presents a new protein based microencapsulation method, which using all food-grade ingredients protects probiotic lactic acid bacteria during exposure to adverse environmental conditions.

Modified Dietary Fiber from Cassava Pulp and Assessment of Mercury Bioaccessibility and Intestinal Uptake Using an In Vitro Digestion/Caco-2 Model System

The ability of modified dietary fiber (MDF) generated from cassava pulp to modulate the bioaccessibility and intestinal absorption of heavy metals may be helpful to mitigate health risk associated with select foods including select fish high in methyl mercury. Using a coupled in vitro digestion/Caco-2 human intestinal cell model, the reduction of fish mercury bioaccessibility and intestinal uptake by MDF was investiaged. MDF was prepared from cassava pulp, a byproduct of tapioca production. The highest yield (79.68%) of MDF was obtained by enzymatic digestion with 0.1% α-amylase (w/v), 0.1% amyloglucosidase (v/v) and 1% neutrase (v/v). MDF and fish tissue were subjected to in vitro digestion and results suggest that MDF may reduce mercury bioaccessibility from fish to 34% to 85% compared to control in a dose-dependent manner. Additionally, accumulation of mercury from digesta containing fish and MDF was only modestly impacted by the presence of MDF. In conclusion, MDF prepared from cassava pulp may be useful as an ingredient to reduce mercury bioavailability from food such as fish specifically by inhibiting mercury transfer to the bioaccessibile fraction during digestion.

Total Phenolic and Flavonoid Contents of Soybean Fermentation by Bacillus subtilis SB-MYP-1

Various fermented soybean, as functional food products, are widely available in worldwide. Total phenolic and flavonoids contents containing in soybean are the potentially health benefit components. In addition, soybean fermentation could enhance the amount of these components. Therefore this study is focused on comparison of total phenolic and flavonoid contents between fermented soybean processed by the application of Bacillus subtilis SB-MYP-1.Soybean and soybean crude extracts that prepared by water and ethanol solvent. The total phenolic and flavonoid contents of fermented soybean crude extracts (FSB) were found significantly higher (p< 0.05) than soybean crude extract (SB). Ethanol FSB showed the highest total phenolic and flavonoid contents at 35.02±0.60 mg gallic acid equivalent/g extract and 14.02±0.66 mg catechin equivalent/g extract while as ethanol SB showed total phenolic and flavonoid contents at 16.94 ± 0.77 mg gallic acid equivalent/g extract and 8.77±0.21 mg catechin equivalent/g extract, respectively. In the same way, water FSB showed the highest total phenolic and flavonoid contents at 29.02 ± 1.37 mg gallic acid equivalent/g extract and 7.02 ± 0.61 mg catechin equivalent/g extract while as water SB showed total phenolic and flavonoid contents at 14.43 ± 0.77 mg gallic acid equivalent/g extract and 5.37 ± 0.24 mg catechin equivalent/g extract, respectively. In conclusion, the fermentation process could enhance total phenolic and flavonoid contents in soybean including ethanol extraction gave higher total phenolic and flavonoid contents in crude extracts. Furthermore, functional properties of both water and ethanol crude soybean extracts should be studied in vitro for beneficial in application in food products and dietary supplement in the near future.

Ultrasound Assisted Extraction for Preparation Dietary Fiber from Cassava Pulp

Dietary fiber is one of value added products from cassava pulp, byproduct of cassava starch industry. It could be produced by enzymatic digestion in which the optimal condition was studied. The three independent variables are heating temperature (°C) after adding α-amylase concentration (%v/v) and amyloglucosidase concentration (%v/v) regarding of two responses solid percentage yield and neutral detergent fiber (NDF) in the digested sample. The experimental design was based on central composite design. The highest solid percentage yield and NDF of cassava byproduct could get from enzymatic digestion condition at heating temperature at 90 °C, α-amylase concentration of 0.3 % (v/v), and amyloglucosidase concentration of 0.5 % (v/v). For ultrasound-assisted preparation was investigated at the optimum condition of enzymatic digestion. Ultrasound condition was control power of 140% and a frequency of 40 kHz for 15 min. The ultrasound was applied at pre-treatment condition (before adding α-amylase, PU) collocated with intermediate condition (before adding amyloglucosidase, IU) higher NDF yield than optimal condition at 18.78%. In addition, this ultrasound assisted technique give the highest solid percentage.

Chlorophylls Contents in Echinocactus grusonii Extract

Currently, Golden Barrel cactus extract is formulated in dietary supplements, on account of its powerful weight loss profit and antioxidant activity. Golden Barrel cactus grusonii (Echinocactus grusonii), a Thai cultivar Golden Barrel cactus which is known as the golden barrel Golden Barrel cactus was therefore investigated for total chlorophylls with the aim of developing as a dietary supplement in future. The chlorophyll contents of 3 and 6 years Echinocactus grusonii extracts were evaluated by High Performance Liquid Chromatography with a Grace-Vydac 201TP54 reversed-phase polymeric C18 column. The results showed that chlorophyll a and chlorophyll b are the main components of Echinocactus grusonii crude extracts also at higher level at age 3 years. It was found that the main chlorophylls contents are chlorophyll a and chlorophyll b at 2.94±0.55μg/ml and 1.63±0.14 μg/ml for 3 years Echinocactus grusonii. In addition, the amount of chlorophyll a and chlorophyll b show lower content at 1.11±0.25μg/ml and 0.67±0.01μg/ml for 6 years Echinocactus grusonii. In conclusion, Echinocactus grusonii age 3 years crude extracts showed total chlorophylls contents higher than at age 6 years. The phytochemical profile study of Echinocactus grusonii age 3 years and 6 years crude extracts are planned in the near future.