Antimicrobial Mechanism of Salt/Acid Solution on Microorganisms Isolated from Trimmed Young Coconut.

This study investigated the inhibitory activity of organic solutions containing 5, 10, 15, 20 and 30% (w/v) sodium chloride and citric acid solution and 15:10, 15:15, 15:20 and 15:30% (w/v) sodium chloride (NaCl) combined with citric acid (CA) solution (salt/acid solution) for 10 min against microorganisms isolated from trimmed young coconut: Bacillus cereus, B. subtilis, Staphylococcus aureus, S. epidermidis, Enterobacter aerogenes, Serratia marcescens, Candida tropicalis, Lodderromyces elongisporus, Aspergillus aculeatus and Penicillium citrinum. Commercial antimicrobial agents such as potassium metabisulfite and sodium hypochlorite (NaOCl) were used as the controls. Results showed that 30% (w/v) NaCl solution displayed antimicrobial properties against all microorganisms, with s reduction range of 0.00-1.49 log CFU/mL. Treatment of 30% (w/v) CA solution inhibited all microorganisms in the reduction range of 1.50-8.43 log CFU/mL, while 15:20% (w/v) salt/acid solution was the minimum concentration that showed a similar antimicrobial effect with NaOCl and strong antimicrobial effect against Gram-negative bacteria. The mode of action of this solution against selected strains including B. cereus, E. aerogenes and C. tropicalis was also determined by scanning electron microscopy and transmission electron microscopy. B. cereus and E. aerogenes revealed degradation and detachment of the outer layer of the cell wall and cytoplasm membrane, while cytoplasmic inclusion in treated C. tropicalis cells changed to larger vacuoles and rough cell walls. The results suggested that a 15:20% (w/v) salt/acid solution could be used as an alternative antimicrobial agent to eliminate microorganisms on fresh produce.

The Effect of Coconut Water on Adipocyte Differentiation and Lipid Accumulation in 3T3-L1 Cells.

Coconut water is reported to have lipid-lowering effects in animal studies. However, there is lack of published reports regarding its effect on adipocytes. This study observed the effect of coconut water on adipocyte differentiation and lipid accumulation in 3T3-L1 cells. The sample used in this study was mature coconut water from tall variety. Based on a preliminary study, the sample was heat-treated and added with certain amino acids as precursors for Maillard reaction to improve its original flavor. As a comparison, aromatic coconut water was used since it is highly preferred as a fresh beverage. Six samples were supplemented to 3T3-L1 cells, which were then analyzed for cell proliferation, lipid accumulation, triglyceride content, and gene expression. Arginine and vitamin C contents of the samples were also determined. The data were analyzed with ANOVA and followed by Tukey's test. Results showed that aromatic coconut water could slightly suppress lipid accumulation, while mature coconut water had a significantly lower percentage of accumulation compared to the control sample (p<0.05). Canned and fresh samples had no significant difference in terms of lipid-lowering activity (p>0.05). Similarly, the addition of lysine and proline in canned samples did not significantly affect the cells' differentiation. There was no significant effect on expressions of C/EBP-α and PPARγ, indicating the possibility of other pathways involved in hypolipidemic effect of coconut water. This study showed that coconut water might have potential to inhibit adipogenesis in 3T3-L1 cells due to its bioactive compounds.

Volatile Aroma Compounds in Jasmine Rice as Affected by Degrees of Milling.

Jasmine rice (Khao Dawk Mali 105) is popular because of its pleasant unique aroma. Milling is an important step in order to produce various types of edible rice. The distribution of volatile aroma compounds in rice especially, endosperm and bran fractions are different. Hence, the purpose of this study was to determine the volatile aroma compounds of low-milled and high-milled Jasmine rice that affect the aroma quality of cooked rice. The new crop of Jasmine paddy was used in this study. Volatile aroma compounds in raw and cooked rice with two degrees of milling, i.e., low-milled rice (2-4% rice bran) and high-milled rice (11-13% rice bran) were investigated. The raw and cooked samples were extracted with dichloromethane and analyzed by gas chromatography-time of flight mass spectrophotometer (GC-TOFMS). The amount of volatile aroma compounds in rice was decreased with high milling. 3-Penten-2-ol (green odor), the most abundant compound in raw rice, was the lowest amount in high-milled rice. On the other hand, the high-milled rice bran had the highest amount of this compound. After cooking, more types of volatile aroma compounds were detected. 2-Acetyl-1-pyrroline (2AP) (pandan-like, popcorn-like) was the most abundant in cooked rice. Meanwhile, hexanal was the highest amount in cooked rice bran. However, 2AP was the potent aroma compound with the highest odor activity values in both raw and cooked rice with low and high milling degree as well as in rice bran.

Solubilization and identification of hen eggshell membrane proteins during different times of chicken embryo development using the proteomic approach.

A fertilized chicken egg is a unit of life. During hatching, transport of nutrients, including calcium, have been reported from the egg components to the developing embryo. Calcium is mobilized from the eggshell with the involvement of Ca(2+)-binding proteins. In addition, other unknown proteins may also play some important roles during embryo developing process. Therefore identification and prediction of biological functions of eggshell membrane (ESM) proteins during chick embryo development was conducted by proteome analysis. Comparison of different lysis solutions indicated that the highest ability to extract ESM proteins could be obtained with 1 % sodium dodecyl sulfate in 5 mM Tris-HCl buffer pH 8.8 containing 0.1 % 2-mercaptoethanol. In this study fertilized Cornish chicken eggs were incubated at 37 °C in humidified incubators for up to 21 days. At selected times (days 1, 9, 15 and 21), samples were taken and the ESMs were carefully separated by hand, washed with distilled water, and air-dried at room temperature. The ESM proteins were then solubilized and analyzed by proteome analysis. Sodium dodecyl sulfate polyacrylamide gel electrophoresis combined with high performance liquid chromatography and mass spectrometry revealed 62 proteins in the ESM; only keratin is known ESM protein, 8 of which are egg white proteins and related while 53 others have not previously been reported. Some differences in the types of proteins and their molecular functions were noted in ESM at different incubation times. One protein which was present only at days 15 and 21 of egg incubation was identified as a calcium binding protein i.e. EGF like repeats and discoidin I like domain 3 (EDIL3 homologous protein).

Inhibitory activity of Asian spices on heterocyclic amines formation in cooked beef patties.

Heterocyclic amines (HCAs) are mutagenic compounds formed when foods are cooked at high temperatures. Numerous reports have shown that natural antioxidants from spices, fruits, chocolate, and tea can inhibit formation. In this study, we evaluated HCA formation in the presence of 5 of Asian spices: galangal (Alpinia galangal), fingerroot (Boesenbergia pandurata), turmeric (Curcuma longa), cumin (Cuminum cyminum), and coriander seeds (Coriandrum sativum). HCA levels were compared to patties containing rosemary (Rosmarinus officinalis), of which the inhibitory effect is well documented. Inhibition of HCA formation by the spices was evaluated in beef patties cooked at 204 °C (400 °F) for 10 min. All spices were mixed into patties at 0.2% before cooking, and HCAs levels were measured in the final product. All patties, including the control, contained 2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl -6-phenylimidazo [4,5-b]pyridine (PhIP). The average HCA content of the control patties was 7 ng/g MeIQx and 6.53 ng/g PhIP. Turmeric (39.2% inhibition), fingerroot (33.5% inhibition), and galangal (18.4% inhibition) significantly decreased HCAs compared with the control. But, only turmeric and fingerroot were as effective as rosemary in preventing HCA formation. The HCA inhibition in patties containing spices was significantly correlated to the total phenolic content (R(2) = 0.80) and the scavenging activity (R(2) = 0.84) of the spices as measured by the 2,2-diphenyl-ß-picrylhydrazyl assay. Results of this study suggest that addition of Asian spices can be an important factor in decreasing the levels of HCAs in fried beef patties.