Effects of molecular weight fraction on antioxidation capacity of rice protein hydrolysates.

Rice protein was used as a starting material to provide rice protein hydrolysates (RPH) through enzyme-assisted extraction. RPH was further fractionated using ultrafiltration membrane (UF) and classified by molecular weight (MW; MW < 1 kDa, MW 1-10 kDa, and MW > 10 kDa). Peptides with MW < 1 kDa possessed superior antioxidant properties (p < 0.05). Therefore, UF demonstrated great efficacy in selectively separating antioxidant peptides. A Pearson correlation analysis revealed that the total phenolic concentration was correlated with oxygen radical absorbance capacity (ORAC; r = 0.999, p < 0.05). Amino acid contents had negative correlations with the scavenging activity (specifically, IC50) of 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals (r = - 0.986 to - 1.000). Reducing power was related to aromatic amino acid contents (r = 0.997, p < 0.05). In this study, enzymatic hydrolysis was discovered to be an effective method of extracting and isolating natural antioxidant proteins from broken rice, thus preserving the nutritional quality of rice and making those proteins more accessible in future applications.

Mulberry Leaf (Morus alba L.) Extracts and Its Chlorogenic Acid Isomer Component Improve Glucolipotoxicity-Induced Hepatic Lipid Accumulation via Downregulating miR-34a and Decreased Inflammation.

Mulberry leaf (Morus alba L.) is used as a traditional medicine and potential health food to treat various metabolic diseases, such as hypertension, diabetes, and hyperlipidemia. However, we sought the mechanisms by which functional components of mulberry leaves mediate diabetic steatohepatitis. We applied an in vitro model of HepG2 cells induced by glucolipotoxicity and evaluated the effects of MLE and its major components nCGA, Crp, and CGA. The results showed that MLE and nCGA reduced liver fat accumulation by inhibiting SREBP-1/FASN, SREBP-2/HMG-CoAR, and activating PPARα/CPT-1. Additionally, MLE and nCGA decreased inflammatory responses associated with NF-κB, TNF-α, and IL-6 to alleviate steatohepatitis. Furthermore, we showed that MLE and nCGA exerted anti-glucolipotoxicity effects by downregulating miR-34a, thus activating SIRT1/AMPK signaling, and subsequently suppressing hepatic lipid accumulation.

Evaluating the Antioxidants, Whitening and Antiaging Properties of Rice Protein Hydrolysates.

Plant-derived protein hydrolysates have potential applications in nutrition. Rice protein hydrolysates (RPHs), an excellent source of proteins, have attracted attention for the development of cosmeceuticals. However, few studies have reported the potential application of RPH in analysis, and this study examined their antioxidant activities and the inhibitory activities of skin aging enzymes. The results indicated that the total phenolic and flavonoid concentrations were 2.06 ± 0.13 mg gallic acid equivalent/g RPHs and 25.96 ± 0.52 µg quercetin equivalent/g RPHs, respectively. RPHs demonstrated dose-dependent activity for scavenging free radicals from 1,1-diphenyl-2-picrylhydrazyl [half-maximal inhibitory concentration (IC50) = 42.58 ± 2.1 mg/g RPHs] and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50 = 2.11 ± 0.88 mg/g RPHs), dose-dependent reduction capacity (6.95 ± 1.40 mg vitamin C equivalent/g RPHs) and oxygen radical absorbance capacity (473 µmol Trolox equivalent/g RPHs). The concentrations of the RPH solution required to achieve 50% inhibition of hyaluronidase and tyrosinase activities were determined to be 8.91 and 107.6 mg/mL, respectively. This study demonstrated that RPHs have antioxidant, antihyaluronidase, and antityrosinase activities for future cosmetic applications.

Implementation of food safety management systems that meets ISO 22000:2018 and HACCP: A case study of capsule biotechnology products of chaga mushroom.

In our study, a food safety management system was developed for a chaga mushroom biotechnology product manufacturer, with the purpose of meeting the quality demands of customers and enhancing the manufacturer's reputation. The study focused on identifying the potentially significant hazards present at each stage of the production process for chaga mushroom capsule products, and on ensuring that the biotechnology company in question has fully implemented ISO22000:2018 and the HACCP methodology. The results indicate that, in the 1 year following the implementation of ISO 22000:2018, there was a statistically significant drop (P < 0.05) in the coliforms level of the tested biotechnology product samples that started in the ninth month following implementation. The rapid screening of mycotoxin, heavy metal, and pesticide residue levels also increased monitoring intensity and strengthened the periodic rotation plan, enabling control over potential problems relating to raw materials and ensuring product quality. This finding reveals the importance and necessity of rapid screening for small- and medium-sized food industry enterprises. Furthermore, 1 year after the system's implementation, the defect rate for chaga products was also observed to have declined, and the number of process flow anomalies requiring correction was also found to have decreased significantly (P < 0.05), indicating that safety and quality levels were improving and stabilizing. If implemented over a longer period of time, the food safety management system's benefits would stand out even more, and significant improvements would be observed for more monitored items. PRACTICAL APPLICATION: Few studies have touched on food safety management systems (FSMSs) developed for capsule health food products. The enterprise examined in this study had actively worked to improve its quality system and meet its customers' needs through the implementation of the FSMSs.

Effects of operating conditions on biogas production in an anaerobic digestion system of the food and beverage industry.

BACKGROUND: Food residuals (FR) were anaerobically biotransformed to produce biogases (e.g. methane and hydrogen), and different pre-treatment conditions, including particle size, oil content, pH and salt content, were controlled in this study. The bio-solids of a municipal solid waste (MSW) from a wastewater treatment plant were added to assess its effect on anaerobic transformation efficiency and gas yields. RESULTS: The breaking of FR and the application of MSW were effective in enhancing the transformation efficiency and yield of biogases. The energy transfer efficiency value of the combined FRs used in this study was probably 23%. However, it can be very cost effective to apply arbitrary proportions to treat two types of FR in the anaerobic digestion tank of a wastewater treatment plant. It was also found that the alkalinity and pH value were two major parameters that controlled the success of the transformation. About 0.16-0.17 kg of alkalinity was needed during the anaerobic digestion of 1 kg dry FR, but this requirement was decreased by the treatment applying MSW. Olive oil had higher reducing rates when used as a substitute for heat-oxidized oil to study the effect of oil content on methylation. CONCLUSION: The conditions for anaerobic digestion established in this study were practical for the digestion of FR in wastewater treatment plants in Taiwan. However, we nonetheless found that it was cost effective to use arbitrary proportions for both types of FR and integrate the anaerobic digestion process used in wastewater treatment plants. © 2020 Society of Chemical Industry.

The Influence of Submerged Fermentation of Inonotus obliquus with Control Atmosphere Treatment on Enhancing Bioactive Ingredient Contents.

This study led in the pioneering technique incubated in a bioreactor with the forced air injection system. The purpose of this study was to establish the optimal incubation conditions for this technique. The results showed that the speed at which Inonotus obliquus was incubated with the forced air injection system was superior to that with a normal bioreactor. A nitrogen to oxygen ratio of 50:50 provided the best results with the forced air injection system, including in terms of the achievement of biomass, total triterpenes, betulinic acid content, and the scavenging activities of DPPH radicals, which reached up to 21.3 g/1000 mL, 2.1 g/1000 mL, 1.9 g/1000 mL, and 87.3%, respectively. The results showed that the bioreactor with the forced air injection system could more effectively incubate I. obliquus by using less vapor while still utilizing a model close to that of a traditional bioreactor. The innovative bioreactor fermentation model was thus more economical than the traditional bioreactor model.

Extracts containing CLPs of Bacillus amyloliquefaciens JN68 isolated from chicken intestines exert antimicrobial effects, particularly on methicillin-resistant Staphylococcus aureus and Listeria monocytogenes.

Bacillus amyloliquefaciens JN68, which has been discussed with regards to its antimicrobial activities, was successfully isolated from healthy chicken intestines in the present study. Using the spot-on-the-lawn antagonism method, the preliminary study indicated that a suspension culture of the B. amyloliquefaciens JN68 strain can inhibit the growth of Aspergillus niger and Penicillium pinophilum. Furthermore, the cyclic lipopeptides (CLPs) produced by the B. amyloliquefaciens JN68 strain were further purified through acid precipitation and Bond Elut®C18 chromatography, and their structures were identified using the liquid chromatography­electrospray ionization­mass spectrometry (MS)/MS method. Purified CLPs exerted broad spectrum antimicrobial activities on various pathogenic and foodborne bacteria and fungi, as determined using the agar well diffusion method. Listeria monocytogenes can induce listeriosis, which is associated with a high mortality rate. Methicillin­resistant Staphylococcus aureus (MRSA) is a major pathogenic bacteria that causes nosocomial infections. Therefore, L. monocytogenes and MRSA are currently of great concern. The present study aimed to determine whether B. amyloliquefaciens JN68 extracts could inhibit L. monocytogenes and MRSA. The results indicated that extracts of B. amyloliquefaciens JN68 have CLP components, and can successfully inhibit the growth of L. monocytogenes and MRSA.

A 90-Day Subchronic Toxicity Study of Submerged Mycelial Culture of Cordyceps cicadae (Ascomycetes) in Rats.

Cordyceps cicadae is a parasitic fungus that hibernates inside a host (Cicada flammata Dist.) and then grows its fruiting body on the surface of the insect. The complete insect/fungus combination of C. cicadae has been widely applied in Chinese traditional medicine. Recent studies have demonstrated that the medicinal benefits of cultured mycelia are as effective as those found in the wild. However, toxicological information regarding the chronic consumption of C. cicadae mycelia culture is not available. This study was conducted to evaluate the possible toxicity arising from repeated exposure to freeze-dried submerged mycelial culture of C. cicadae for 90 days. A total of eighty 8-week-old Sprague-Dawley rats were divided into 4 groups (10 males and 10 females in each group). C. cicadae was administered daily to animals by gavage at doses of 0, 500, 1000, and 2000 mg/kg body weight for 90 days. No animal deaths occurred and no treatment-related clinical signs were observed during the study period. No statistical differences in body weight gain, relative organ weight, hematology, serum chemistry, and urinalysis were observed. Gross necropsy and histopathological findings indicated that there was no treatment-related abnormality. Based on the results, the no observed adverse effect level of C. cicadae whole broth is determined to be > 2000 mg/kg for male and female Sprague-Dawley rats. The results of this study provides support for the use of C. cicadae fermentation product as a safe agent in functional food.

Ascorbic acid inhibits TPA-induced HL-60 cell differentiation by decreasing cellular H2O2 and ERK phosphorylation.

Retinoic acid (RA), vitamin D and 12-O­tetradecanoyl phorbol-13-acetate (TPA) can induce HL-60 cells to differentiate into granulocytes, monocytes and macrophages, respectively. Similar to RA and vitamin D, ascorbic acid also belongs to the vitamin family. High­dose ascorbic acid (>100 µM) induces HL­60 cell apoptosis and induces a small fraction of HL­60 cells to express the granulocyte marker, CD66b. In addition, ascorbic acid exerts an anti­oxidative stress function. Oxidative stress is required for HL­60 cell differentiation following treatment with TPA, however, the effect of ascorbic acid on HL­60 cell differentiation in combination with TPA treatment remains to be fully elucidated. The aim of the present study was to investigate the cellular effects of ascorbic acid treatment on TPA-differentiated HL-60 cells. TPA-differentiated HL-60 cells were used for this investigation, this study and the levels of cellular hydrogen peroxide (H2O2), caspase activity and ERK phosphorylation were determined following combined treatment with TPA and ascorbic acid. The results demonstrated that low­dose ascorbic acid (5 µM) reduced the cellular levels of H2O2 and inhibited the differentiation of HL­60 cells into macrophages following treatment with TPA. In addition, the results of the present study further demonstrated that low­dose ascorbic acid inactivates the ERK phosphorylation pathway, which inhibited HL­60 cell differentiation following treatment with TPA.

Rana catesbeiana ribonuclease induces cell apoptosis via the caspase-9/-3 signaling pathway in human glioblastoma DBTRG, GBM8901 and GBM8401 cell lines.

Human glioblastoma multiforme is one of the most aggressive malignant brain tumor types, and the mean survival time of patients with a brain tumor is <2 years when traditional therapies are administered. Thus, numerous studies have focused on the development of novel treatments for brain tumors. Frog ribonucleases, such as Onconase and Rana catesbeiana ribonuclease (RC-RNase), exert antitumor effects on various tumor cells, including cervical cancer, breast cancer, hepatoma, leukemia, pancreatic cancer and prostate cancer cells. In addition, frog Onconase has been applied as a treatment in clinical trials. However, the antitumor effects of frog ribonucleases on brain tumors are unclear. Previous studies have indicated that RC-RNase demonstrates a decreased cytotoxic effect in normal cells compared with Onconase. Therefore, the present study investigated the ability of RC-RNase to exert antitumor activities on human glioblastoma. It was found that RC-RNase inhibits the growth of the human glioblastoma DBTRG, GBM8901 and GBM8401 cells. In addition, the present study revealed that RC-RNase induces caspase-9/-3 activity and triggers the apoptotic cell death pathway in human glioblastoma cells. Notably, it was also demonstrated that RC-RNase effectively inhibits the growth of human glioblastoma tumors in a nude mouse model. Overall, the present study indicates that RC-RNase may be a potential agent for the treatment of human glioblastoma.

Effects of blending wheatgrass juice on enhancing phenolic compounds and antioxidant activities of traditional kombucha beverage.

Traditional kombucha is a fermented black tea extract and sugar. Sweetened black tea (10% w/v) and wheatgrass juice (WGJ) were mixed in various ratios and used as fermentation substrate for enhancing phenolic compounds and antioxidant activity. Starter, comprising of yeast (Dekkera bruxellensis) and acetic acid bacteria (Gluconacetobacter rhaeticus and Gluconobacter roseus), was inoculated at 20% (v/v), and fermented statically at 29 ± 1°C for 12 days. The results showed that the total phenolic and flavonoid contents and antioxidant activity of the modified kombucha were higher than those of traditional preparations. All WGJ-blended kombucha preparations were characterized as having higher concentrations of various phenolic compounds such as gallic acid, catechin, caffeic acid, ferulic acid, rutin, and chlorogenic acid as compared to traditional ones. Addition of WGJ resulted in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability of kombucha being > 90%, while the oxygen radical absorbance capacity increased from 5.0 µmol trolox equivalents/mL to 12.8 µmol trolox equivalents/mL as the ratio of WGJ increased from 0% to 67% (v/v). The highest antioxidant activity was obtained using a 1:1 (v/v) black tea decoction to WGJ ratio and 3 days of fermentation, producing various types of phenolic acids. These results suggest that intake of fermented black tea enhanced with wheatgrass juice is advantageous over traditional kombucha formulas in terms of providing various complementary phenolics and might have more potential to reduce oxidative stress.

Evaluation of the toxicological safety of erinacine A-enriched Hericium erinaceus in a 28-day oral feeding study in Sprague-Dawley rats.

Natural products have attained great importance as they are believed to be the new alternative medicines for conventional therapy. As numerous studies have proved the tremendous medicinal values of Hericium erinaceus, it is necessary to take into account its safety as well as its risk for the recipient. However, mushroom mycelium has an identity distinct from mushrooms, as two specific classes of compounds, hericenones and erinacines, can only be extracted from both the fruit body and the cultured mycelium, respectively. Therefore, this is the first report on the evaluation of the toxicity of H.erinaceus mycelium, enriched with 5mg/g erinacine A, by a 28-day repeated oral administration study in Sprague-Dawley rats. Three doses of 1 (Low), 2 (Mid) and 3 (High) g/kg body weight/day were selected for the study while distilled water served as control. All animals survived to the end of the study. No abnormal changes were observed in clinical signs. No adverse or test article-related differences were found in urinalysis, haematology and serum biochemistry parameters, between the treatment and control groups. No gross pathological findings and histopathological differences were seen. Therefore, the no-observed-adverse-effect level of erinacine A-enriched H.erinaceus is greater than 3g/kgbody weight/day.

Simultaneous production of fatty acid methyl esters and diglycerides by four recombinant Candida rugosa lipase's isozymes.

In this study, the catalytic efficiency of four recombinant CRL (Candida rugosa lipase) isozymes (LIP1-LIP4) towards the production of fatty acid methyl ester (FAME) was compared and evaluated as an alternative green method for industrial applications. The results indicated that the recombinant C. rugosa LIP1 enzyme exhibited the highest catalytic efficiency for FAME production compared to the recombinant C. rugosa LIP2-LIP4 enzymes. The optimal conditions were as follows: pH 7.0, methanol/soybean oil molar ratio: 3/1, enzyme amount: 2U (1.6 µL), reaction temperature: 20°C, 22 h of reaction time, and 3 times of methanol addition (1 mol/6h), and resulted in 61.5 ± 1.5 wt.% of FAME conversion. The reaction product contained also 10 wt.% of DAG with a ratio of 1,3-DAG to 1,2-DAG of approximately 4:6, and can be potentially used in industrial applications as a food emulsifier.

Genotoxicity profile of erinacine A-enriched Hericium erinaceus mycelium.

Hericium erinaceus (H. erinaceus) has a long history of usage in traditional Chinese medicine for the treatment of gastric disorders. Recently, it has become a well-established candidate in causing positive brain and nerve health-related activities by inducing nerve growth factor (NGF) from its bioactive ingredient, erinacine A. This active compound, which exists only in fermented mycelium but not in its fruiting body, increases NGF levels in astroglial cells in vitro as well as catecholamine and NGF levels in vivo. With increasing recognition of erinacine A in H. erinaceus (EAHE) mycelium improving neurodegenerative diseases, numerous products are being marketed based on these functional claims. To our knowledge, there have been no reports on the mutagenicity of EAHE prior to this paper. Hence, the present study was undertaken to determine the mutagenicity and genotoxicity effects of EAHE mycelium conducted in three standard battery of tests (reverse mutation, chromosomal aberration, and micronuclei tests) according to the latest guidelines in order to meet all international regulatory requirements and provide information on the safety of this new and promising natural remedy. Our results have indicated that EAHE mycelium did not significantly increase the number of revertant colonies in the bacterial reverse mutation test nor induce higher frequency of aberrations in the chromosome aberration test. Moreover, no statistically significant EAHE mycelium-related increase was observed in the incidence of reticulocytes per 1000 red blood cells and micronucleated reticulocytes per 1000 reticulocytes. In conclusion, the three standard battery of tests suggested that EAHE mycelium was devoid of mutagenicity and genotoxicity in the tested doses and experimental conditions.

Enhancement of the immune response against Salmonella infection of mice by heat-killed multispecies combinations of lactic acid bacteria.

Heat-killed lactic acid bacteria (LAB) has advantages over live LAB in that it has a long shelf-life and is therefore easy to store and transport. From four LAB strains selected by immunomodulatory activity and adherent properties, we prepared the heat-killed multispecies combination of LAB (MLAB) and the cell walls from MLAB under two conditions (100 °C for 30 min and 121 °C for 15 min). Different effects on the adherent properties of these four LAB strains were observed, depending on the heating conditions. With mouse macrophage cells, the two heat-killed MLABs (HMLABs) showed significantly higher induction activities on the production of interleukin 12 (IL-12) than their individual strains did. Heat-killed MLABs and cell-wall preparations were able to reduce the Salmonella invasion of Caco-2 and mouse macrophage cells. Feeding mice with HMLAB could inhibit the Salmonella invasion of mice significantly. For these mice, the expression level of pro-inflammatory cytokines, such as TNF-α and IL-6, in mouse serum was reduced while that of the anti-inflammatory cytokine, i.e. IL-10, was enhanced. The HMLABs developed in this study showed higher protective effect against Salmonella invasion either of Caco-2 cells or of mice, relative to the heat-killed lactobacilli, which consisted of Lactobacillus acidophilus strains selected at random. In conclusion, the HMLABs were potentially useful for the protection of mice against Salmonella infection and the induced inflammation.

Simultaneous production of trehalose, bioethanol, and high-protein product from rice by an enzymatic process.

Rice is a starch-rich raw material that can be used for trehalose production. It can be hydrolyzed with alpha-amylase, beta-amylase, and pullulanase to produce high-maltose content of rice saccharified solution for bioconversion of maltose into trehalose by trehalose synthase (TSase). For this purpose, an efficient enzymatic procedure has been successfully developed to simultaneously produce value-added trehalose, bioethanol, and high-protein product from rice as substrate. The highest maltose yield produced from the liquefied rice starch hydrolysate was 82.4 +/- 2.8% at 50 degrees C and pH 5.0 for 21-22 h. The trehalose conversion rate can reach at least 50% at 50 degrees C and pH 5.0 for 20-24 h by a novel thermostable recombinant Picrophilus torridus trehalose synthase (PTTS). All residual sugar, except trehalose, can be fully hydrolyzed by glucoamylase into glucose for further bioethanol production. The insoluble byproduct containing high yields of protein (75.99%) and dietary fiber (14.01%) can be processed as breakfast cereal product, health food, animal forage, etc. The conversion yield of bioethanol was about 98% after 64 h of fermentation time by Saccharomyces cerevisiae without any artificial culture solution addition. Ethanol can easily be separated from trehalose by distillation with a high recovery yield and purity of crystalline trehalose of 92.5 +/- 8.7% and 92.3%, respectively.

High dose vitamin C supplementation increases the Th1/Th2 cytokine secretion ratio, but decreases eosinophilic infiltration in bronchoalveolar lavage fluid of ovalbumin-sensitized and challenged mice.

Vitamin C is traditionally regarded to be beneficial for asthma, however the benefit is still controversial. In the present study, high dose vitamin C was supplemented to ovalbumin (OVA)-sensitized and challenged mice to evaluate the effects of dietary vitamin C on allergic asthma. In this study, the experimental mice were divided into four groups, including nonsensitized control, dietary control, positive control (cured ip with dexamethasone), and high dose vitamin C supplementation (130 mg of vitamin C/kg bw/day by gavage for 5 weeks). Differential leukocyte counts, levels of inflammatory mediators, as well as type 1 T-helper lymphocytes (Th1)-type and type 2 T-helper lymphocytes (Th2)-type cytokines in the bronchoalveolar lavage fluid (BALF) were determined. The results showed that both high dose vitamin C supplementation and dexamethasone treatments significantly (P < 0.05) decreased eosinophilic infiltration into BALF. High dose vitamin C supplementation significantly increased the secretion ratio of interferon (IFN)-gamma/interleukin (IL)-5 cytokines. This study suggests that high dose vitamin C supplementation might attenuate allergic inflammation in vivo via modulating the Th1/Th2 balance toward the Th1 pole during the Th2-skewed allergic airway inflammation and decreasing eosinophilic infiltration into BALF.

Dietary perilla oil lowers serum lipids and ovalbumin-specific IgG1, but increases total IgE levels in ovalbumin-challenged mice.

Our previous studies indicated that alpha-linolenic acid (ALA)-rich perilla oil might alleviate bronchoalveolar inflammation. However, it failed to modulate the Th1/Th2 balance toward the Th1 pole during Th2-skewed allergic airway inflammation in mice. This study attempts to further investigate the effects of dietary perilla oil on serum lipids and immunoglobulin profiles using an ovalbumin (OVA)-challenged mouse model. The inbred female BALB/c mice were randomly divided into four groups and fed different AIN-76 feeds containing 5% corn oil (rich in linoleic acid, 18:2n-6 polyunsaturated fatty acids (PUFA), as a control diet), 5% perilla oil (rich in alpha-linolenic acid, 18:3n-3 PUFA) or 5% compound oil containing 50% corn oil and 50% perilla oil, respectively, for 35 consecutive days ad libitum. Experimental mice were sensitized by an intraperitoneal injection of alum-precipitated antigen containing ovalbumin on 7, 14 and 21 days after supply of the specified experimental diets. One week later, the mice were then challenged by aerosolized OVA. The results showed that dietary perilla oil administration significantly (P < 0.05) decreased the relative liver tissue weight (RTW) and serum lipid levels including triglycerides, total cholesterol, HDL- and LDL-cholesterol. However, the HDL/LDL ratio was also significantly lowered by dietary perilla oil. Dietary perilla oil markedly decreased serum OVA-specific IgG1 level and total IgA antibodies (Th2 antibodies). Unfortunately, it also increased non-specific serum IgE (Th2 antibody) levels. The results suggest that dietary perilla oil might have a moderately beneficial effect on asthmatic allergy via lowering serum lipids and OVA-specific IgG1, as well as total IgA levels. However, it failed to obviously modulate Th1/Th2 antibody levels via isotype switching of B cells from Th2 antibody to Th1 antibody.

Effect of microbial fermentation on content of statin, GABA, and polyphenols in Pu-Erh tea.

Besides cancer prevention, the hypolipidemic effects of tea have been well studied in animals and humans. Recently, statin has been identified in Pu-erh tea extract. Clinical trials have confirmed that statin decreases the incidence of major coronary and cerebrovascular events and this may be due to its hypolipidemic and antiinflammatory effects. Since a good Pu-erh tea needs longer storage (10 years or more) of fermentation to enhance the flavor and fragrance, we screened microorganisms from two Pu-erh teas, 20 and 25 years old. Species of fungi and bacteria strains that contributed to a good taste of Pu-erh tea were isolated. The effect of fermentation was investigated by inoculating fresh tea leaves with individual strains of isolated microorganisms. Results showed that statin, total polyphenol content, and the scavenging activities of alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radicals increased during fermentation. Tea leaves inoculated with Streptomyces bacillaris strain R9 had the highest polyphenol content (3.3 mg/100 g) and scavenging ability to DPPH radicals (92%). Streptomyces cinereus strain Y11 was equally good for polyphenol content but yielded the highest amount of statin (1012 ng/g) after 42 days of fermentation. Interestingly, the statin content of fresh tea leaves fermented with strain R9 or Y11 after 180 days was much higher (4- and 8-fold, respectively) than that of the 25-year-old Pu-erh tea (513 ng/g) as measured by the HPLC method. Similarly, these two strains also increased the content of gamma-aminobutyric acid (GABA) 5.7- and 4.7-fold in tea fermented for 180 days as compared with the fresh leaves (1270 microg/g) and that were higher than that of the Pu-erh tea (4900 microg/g). Taken together, the present results indicate that tea short-term fermented with S. bacillaris or S. cinereus enhances the color and content of statin, GABA, and polyphenols.

An antifungal chitinase produced by Bacillus cereus with shrimp and crab shell powder as a carbon source.

The production of inexpensive chitinolytic enzymes is an element in the utilization of shellfish processing wastes. In this study, shrimp and crab shell powder prepared by treating shrimp and crab processing wastes with boiling and crushing was used as a substrate for the isolation of an antifungal chitinase-producing microorganism. Bacillus cereus YQ 308, a strain isolated from the soil samples, excreted one chitinase when cultured in a medium containing 2% (wt/vol) shrimp and crab shell powder as major carbon source. The chitinase, purified by sequential chromatography, had an Mr of 48 kDa and pI of 5.2. The purified chitinase (2 mg/ml) inhibited the hyphal extension of the fungi Fusarium oxysporum and Pythium ultimum.