Several studies have shown that green tea catechins reduce serum and liver cholesterol concentrations and increase the fecal excretion of neutral steroids originating from cholesterol in experimental animals. Furthermore, we have found that green tea catechins, particularly, their galloyl esters, could reduce the lymphatic absorption of cholesterol in rats. This finding suggests that green tea catechins having a galloyl moiety can inhibit cholesterol absorption in the intestine, thus reducing serum cholesterol concentration. The solubilization of cholesterol in bile salt micelles is essential for its absorption. Catechins having a galloyl moiety can decrease the micellar solubility of cholesterol; however, it is not well understood how these catechins decrease micellar solubility. This review presents novel mechanisms underlying the decrease in cholesterol micellar solubility mediated by catechins having a galloyl moiety.
This study aimed to develop a new prebiotic dairy dessert by adding different concentration of cereal flours (10 – 16% w/w), inulin (6 and 8% w/w) and sugar (2 and 4% w/w) into dairy dessert formulation. A mixture design approach was used to create nine formulation of dessert samples. Desserts were evaluated by consumers who were asked to answer a check-all-that-apply (CATA) question. Water holding capacity (WHC) and syneresis values were also measured. Based on our results different concentration of flour, inulin and sugar resulted in different sensory and rheological properties. Dessert samples with higher content of inulin and sugar had lesser consistency coefficient and storage modulus. Samples with higher level of flour and lower level of inulin and sugar had good physical stability and presented appropriate sensory characteristics. Results showed that data from both consumers' response to CATA question and rheological measurements presented the same information.
The caproic acid-producing bacterial consortium (CAPBC) J30, isolated from Chinese Luzhou-flavored liquor distillery's pit mud, produces caproic acid as a metabolite. Constructed a 16S rDNA gene clone library and analyzed amplified ribosomal DNA restriction analysis, Clostridium genus was found predominating in CAPBC J30 and C. kluyveri was the chief contributor to its caproic acid-producing ability. Then based on the Daqu extraction medium, effects of different carbon sources, nitrogen sources and growth factors on the caproic acid-producing ability were investigated, among which six key factors were chosen and optimized by Taguchi design. The estimated optimal medium was the Daqu extraction medium added 10 g·l−1sodium acetate, ethanol 15 ml·l−1, liquor tailing 15 ml·l−1, urea 3 g·l−1, yellow mud extraction 1 ml·l−1, and (NH4)2SO4 0.5 g·l−1. After cultivated in this optimized medium for 15 days at 37°C, the caproic acid yield was up to 5024.11 mg·l−1. This optimal medium will help to produce high caproic acid of CAPBC J30 to circumvent bottlenecks encountered in the high effective and adaptable ingredients in the field of Chinses Luzhou-flavored liquor manufacture.
Studies were performed to investigate the Cadmium (Cd) distribution and Cd-binding proteins in rice kernel. Rice seeds [Oryza sativa L. (Akitakaomachi)] were cultured under Cd stress and after harvesting, the Cd distribution was determined using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The Cd concentrations and amino acid compositions in different storage protein fractions were analyzed using ICP-MS and an amino acid analyzer, respectively. The molecular weights of the Cd-binding proteins were determined by size exclusion chromatography-inductively coupled plasma mass spectrometry (SEC-ICP-MS). The Cd concentrations in rice kernel gradually decreased from the outer bran layers to the endosperm and Cd was particularly concentrated in the embryo, the outer pericarp and the aleurone layer. The Cd concentrations in different proteins fractions decreased in the following sequence: globulin > albumin > glutelin > prolamin. The presence of cysteine and methionine were closely related to the Cd concentration. The molecular weights of three prominent Cd-binding protein fractions were > 2000 k Da, 570 k Da and 131.9 k Da, respectively.
Abnormal accumulation of melanin causes unaesthetic hyperpigmentation. Many studies suggest that yogurt have some effects of antioxidant and anti-aging. In this study, the antioxidant and melanogenesis-inhibitory activity of fermented milk supernatant (FMS) prepared by Lactobacillus plantarum CGMCC8198, a novel probiotics strain, were detected. The results in both ABTS and DPPH assay showed that FMS exhibited markedly antioxidant effect. Melanin production was significantly reduced by FMS, while the survival of cells was not affected. Furthermore, FMS reduced the activity of cellular tyrosinase but had no effect on tyrosinase itself, and the results of RT-PCR, Western blot and immunocytochemistry demonstrated that FMS could inhibit the transcription and expression of tyrosinase, TRP-1, TRP-2 and MITF, and these effects were mainly depended on heated-resistant macromolecule substances. Our results suggested that Lactobacillus plantarum CGMCC8198-Fermented Milk could be a good candidate for antioxidant and treating hyperpigmentation disorders and could also be used as a cosmetic whitening agent.
The prevalence of Staphylococcus aureus in dairy products in North Africa is high. Biopreservation promises to be one of the most sustainable strategies for reducing the risk of this pathogen. In this perspective, we screened local raw milk samples for LAB strains exhibiting anti-pathogenic activity against S. aureus and 11 other notorious food-borne pathogens. From the initial 120 LAB isolates, we selected the best-performing strains based on the breadth of their anti-pathogenic activity spectra. Lactobacillus paracasei subsp. paracasei KU517839 showed the best antibiosis against S. aureus with inhibition zones of (3.53 ± 0.05 cm) and the largest antibacterial activity spectrum as it inhibited all the other 11 pathogenic strains. Furthermore, a reduction of 5 log in S. aureus cell number was registered in fermented milk co-cultures and it significantly inhibited its growth in fresh cheese (8 log reduction; p < 0.001) even after 21 days of storage at 4°C.
Changes in ginsenoside composition of ginseng at high temperatures (110, 130, and 150°C) under various soaking conditions (0 – 100% ethanol solutions) were determined. The total ginsenoside contents (20.57 – 27.99 mg/g) of heat-processed ginsengs (HG) at 110 and 130°C were higher than raw ginseng (16.96 mg/g). Group A's ginsenosides (Rg1, Re, Rf, Rb1, Rc, Rg2(S), Rb2, Rb3, and Rd) decreased with increasing temperatures and decreasing ethanol concentrations, whereas those of group B (Rh1, Rg2(R), Rg6, F2, F4, Rk3, Rh4, Rg3(S), Rg3(R), Rk1, Rg5, and Rh2) showed the opposite trend. Significant correlations were observed among groups A and B, ethanol concentration, and the processing temperature. This study suggests that the composition and content of ginsenosides are dependent on the processing temperatures and ethanol concentrations, and ginsenoside composition can be altered and its content can be manipulated by adjusting the processing temperatures and ethanol concentrations of soaking solutions.
The water solubility of rice bran protein (RBP) was improved by deamidation under alkaline conditions. The degree of deamidation was found to be a major factor in improving the solubility of RBP. The decrease in molecular mass or the degradation of peptide bonds was not detected in deamidated RBP under the conditions used. The thermal property and secondary structure of deamidated RBP measured by differential scanning calorimetry and Fourier transform infrared spectroscopy indicated that the secondary structure of RBP was well preserved during alkaline deamidation. By raising pH and temperature for deamidation, the generation rates of constituent amino acid racemization and lysinoalanine increased. The highest solubility (∼90%) of RBP was achieved by treatment at pH 12 and 120°C for 15 – 30 min by enduring side reactions. Moderate solubility (∼40%) could be achieved by deamidation at pH 8 and 100°C for 30 min to minimize side reactions.
This study aimed to investigate the effects of areca flower tea polyphenol extract (AFPE) on the adipogenesis of 3T3-L1 preadipocytes. AFPE was extracted from areca flower tea using boiling water, and the polyphenolic compounds were analysed by HPLC. At doses that they did not induce cytotoxicity, AFPE (50 – 200 µg/mL) efficiently inhibited triglyceride accumulation in the mature adipocytes in a dose-dependent manner when induced to differentiate. Additionally, AFPE suppressed the secretion of leptin and the expression of lipoprotein lipase (LPL). Moreover, the anti-adipogenic properties were also attributed to the down-regulation of protein expression of major transcriptional factors in adipogenesis, including peroxisome proliferator-activated receptor γ (PPARγ) and CCAT/enhancer-binding protein α (C/EBPα). Therefore, these results suggest that AFPE may prevent obesity by inhibiting the differentiation of preadipocytes, suggesting its potential application in functional foods and nutraceuticals for obesity management.
In this study, we investigated the effects of dietary protein types during late pregnancy on hyaluronan metabolism in the skin of newborn mice. Levels of hyaluronan and hyaluronan synthase (Has)2 mRNA expression increased in the skin of newborn mice from dams fed the gluten diet during pregnancy (Gluten group) when compared with those of newborn mice from dams fed the soy protein diet during late pregnancy (Soy group). In contrast, skin mRNA expression of KIAA1199, which plays a primary role in hyaluronan degradation in the dermis, decreased in the Gluten group. These results show that a maternal low-quality protein diet increases hyaluronan levels, modulates Has2 and KIAA1199 mRNA expression in the skin of newborn mice.
The anti-inflammatory activity of Grifola gargal was evaluated using an in vitro gut inflammation model composed of RAW264.7 and Caco-2 cells. The active compound was isolated and purified to elucidate its structure by instrumental analysis. A low-molecular-weight fraction in G. gargal prepared using an ultrafiltration membrane (13 000 Da molecular-weight cut-off) suppressed tumor necrosis factor-α production and interleukin-8 mRNA expression in an in vitro gut inflammation model. The low-molecular-weight fraction was subjected to sequential extraction, consisting of reverse-phase extraction using 0 – 100% ethanol, in 20% steps, and high-performance liquid chromatography to separate and purify the active compound with anti-inflammatory activity. Instrument analyses indicated that adenine was one of the active compounds. It was suggested that adenine in G. gargal had no small effect on the suppression of inflammatory bowel disease.
Wheat bran has a high dietary fiber content. In this study, we investigated the effects of short-term intake of wheat bran on intestinal environment in a murine model. Mice were fed with AIN-93G for 1 week, followed by experimental diets containing wheat bran with an average particle size of 53 µm (powdered) or 350 µm (granulated) for 1 additional week. During a 4-week period (twice-repeated feeding cycles), the ratio of bacteria belonging to the families Prevotellaceae and S24-7 increased in murine feces after intake of both particle-size diets. Furthermore, the amount of short fatty acids, particularly butyric acid, and cecal immunoglobulin A were significantly increased in the powdered wheat bran group, probably by the changes in intestinal microbiota composition. These findings may potentially explain many of the health benefits through the alteration of intestinal microbiota, even after short-term intake of wheat bran.
We studied the effects of κ-casein (κ-CN) dissociation from casein micelles upon heating on cheese curd formation. Cheese curd was formed by the addition of chymosin to unheated and heated (80°C, 30 min) defatted milk. In heated defatted milk, cheese curd was not formed; however, the amount of free glycomacropeptides (GMPs) and the degree of formation of para-κ-CN were the same in both the unheated and heated defatted milk. In addition, because calcium ions insolubilize upon heating, the calcium ion concentration in the heated defatted milk was adjusted to its equivalent amount in the unheated defatted milk; however, cheese curd was not formed in this case either. Therefore, chymosin was added to the casein micelles, which dissociated κ-CN. As a result, the amount of free GMP was significantly less (p < 0.05) than that in the native casein micelles. The results suggest that the quantity of formation of para-κ-CN on the micelle surface decreases due to κ-CN dissociation from the casein micelles.
Some γ-aminobutyric acid (GABA) producing and nitrite reducing lactic acid bacteria were isolated from Sichuan paocai, a Chinese traditional fermented vegetable. Determination of GABA and sodium nitrite residue was carried out by thin layer chromatography combined with HPLC and colorimetric analysis, respectively. It was found that BC114 strain which was identified and designated as Lactobacillus plantarum BC114 possessed the highest GABA producing and nitrite degradation capacity in MRS broth with 5 g/L monosodium glutamate (MSG) and 100 mg/L sodium nitrite. Then, GABA production and nitrite degradation ability were enhanced by optimizing culture conditions, such as time, pH, temperature and MSG concentration. The greatest yield (3.45 g/L) of GABA was determined after 72 h fermentation in MRS with 20 g/L MSG at 30°C and initial pH 5.5. Furthermore, nitrite degradation ability reached the maximum value of 90.17%. These results suggested that L. plantarum BC114 with GABA producing and nitrite reducing ability has the potential to be starter culture and promote the development of functional fermented foods.
The effects of γ-amino butyric acid (GABA)-rich salted radish pickles on blood pressure were evaluated. Raw radish roots were dehydrated under the sun, then pickled with salt. GABA concentrations in the radish roots dramatically increased during dehydration, and decreased slightly after pickling. Male spontaneously hypertensive rats (SHR/Izm) consumed AIN-76 based diets containing 0.3% salted pickle powder or equivalent amounts of GABA (0.002%) and sodium chloride (0.055%). After two weeks, the increased systolic blood pressure observed in the control SHR group was significantly prevented in both sample groups at similar potencies, indicating that the consumption of salted pickles lowered blood pressure. Furthermore, one of the active compounds might be GABA, while sodium chloride in the salted pickles might not affect the positive effects on blood pressure observed in SHR fed salted pickles. In conclusion, the daily consumption of GABA-rich salted pickles may be ideal for lowering blood pressure.
Raw soymilk separates into two layers (upper and lower) upon freeze-thawing. In this study, we investigated the effects of heating (50 – 95°C) before freezing on the freeze-thaw fractionation of soymilk. Proportion of the upper layer decreased as the heating temperature before freezing was elevated, and heating at 80°C completely inhibited the fractionation. The amount of protein in the upper layer decreased with higher heating temperatures, and the 7S globulin contents in the lower layer increased simultaneously. The particle size of the upper layer decreased with increased heating temperatures, whereas the particle size of the lower layer increased at temperatures greater than about 70°C. These results suggested that the changes in soymilk fractionation are likely due to the liberation of 7S globulin from lipid/protein complexes upon heating, and interactions among the proteins and lipid/protein complexes caused by freeze-mediated concentration.