Correlation study between standard plate count and flow cytometry for determination of raw milk total bacterial count

Milk samples were collected in the dry season ( n =  155) and in the rainy season ( n =  68) to establish a correlation between electronic flow cytometry and standard plate count for the determination of total bacterial count of raw milk. Results were expressed in individual bacterial count (ibc) and colony forming unit (cfu) for electronic flow cytometry (Bactocount) and standard plate count, respectively. The accuracy of Bactocount, denoted by the residual standard deviation ( s ( y,x )), was 0.309 log cfu/mL. The predictive interval of estimated values was broad and it is suggested that total bacterial count should be expressed in ibc without transformation to cfu.     

STORAGE RESULTS IN LOSS OF THE ANTIGENOTOXIC PROPERTIES OF LENTINULA EDODES (SHIITAKE MUSHROOM) AND DEVELOPMENT OF IN VIVO GENOTOXICITY

In this study, we have investigated the stability of the antigenotoxic properties of dried of Lentinula edodes (Berk.) Singer mushroom powder stored at room and at − 20C. Mice were pretreated by gavage for 15 consecutive days with 0.6 mL/day of an aqueous extract of dried L. edodes powder prepared at 60C. On day 15, the mice were intraperitoneally injected with 50 mg/kg N-ethyl-N-nitrosourea (ENU); 3 h later, peripheral blood was withdrawn from the animals and used to evaluate DNA damage using the comet assay. The mice were sacrificed 24 h after the ENU treatment and the bone marrow used to measure the frequency of micronucleated polychromatic erythrocytes. The results indicated that storage at both room temperature and at − 20C significantly reduced the antigenotoxic effects of the mushroom powder. In addition, whereas freshly dried mushroom powder was nongenotoxic, storage of the powder at − 20C resulted in genotoxic activity ( P <  0.05). Taken together, our data indicate that constituents of L. edodes powder are altered during storage, resulting in both genotoxicity and a reduction in antigenotoxicity.     

THE USE OF RHEOLOGY TO CHARACTERIZE FLOW BEHAVIOR OF LIQUORICE SOLUTIONS

The rheological behavior of liquorice solutions at different concentrations (ranging between 30 and 60 Brix) and temperatures (in the range between 25 and 80C) has been investigated performing both dynamic tests in the linear viscoelastic region and steady shear tests, in 0.1–100 s^?1 shear rate range, by using a stress controlled rheometer (DSR 200, Rheometric Scientific, USA) and parallel plate geometry (φ = 40 mm). Small amplitude oscillations has shown the presence of both moduli also at the lowest tested concentration, with G′ greater than G″, except for the 30 Brix sample. It has been found that experimental viscosity data show a good agreement with a power law model, thus allowing the estimation of both the friction factor and the pressure drops in a typical pipeline used for liquorice solution conveying. It has been observed that the assumption of Newtonian behavior can lead to the erroneous design of the apparatuses that have to process liquorice extracts.     

大青叶抗菌物质提取及抗菌效果研究

研究了用水浸提法抽提大青叶中抗菌物质的方法，并通过抑菌实验检验了对细菌和霉菌的抑菌能力。正交实验结果表明最佳抽提工艺为：料水比1：20，加热时间40min，回流温度100℃：滤纸片法抑菌实验发现：大青叶提抽浓缩液(浓缩比为5：1)对大肠杆菌及枯草杆菌的最低抑菌浓度为2．77％(ml，100ml)左右，青霉，黄曲霉为0．55％(ml／100ml)左右，金黄色葡萄球为0．055％(ml／100ml)左右。     

Lacticaseibacillus paracasei K71 Alleviates UVB-Induced Skin Barrier Dysfunction by Attenuating Inflammation via Increased IL-10 Production in Mice

Scope

Ultraviolet B (UVB) radiation causes skin barrier dysfunction, leading to decreased water-holding capacity, impaired epidermal barrier function, and increased skin thickness. This study investigates the protective effects of oral administration of Lacticaseibacillus paracasei K71 against skin barrier dysfunction in UVB-irradiated mice.

Methods and results

Mice are fed diets with or without K71 and irradiated with UVB three times a week for 12 weeks. Oral administration of K71 suppresses UVB-induced decrease in stratum corneum water content, mitigates the increase of transepidermal water loss, and decreases epidermal thickness of the dorsal skin. Treatment with K71 reverses the upregulation of inflammatory cytokines and the activation of nuclear factor-κB induced by UVB irradiation and upregulates the expression of anti-inflammatory IL-10 in the dorsal skin. Notable upregulation of IL-10 is observed in the spleens of K71-treated mice. K71 treatment enhances IL-10 production in J774.1 macrophages; however, this enhancement is diminished by inhibiting K71 phagocytosis and TLR3. Furthermore, transfection using K71 RNAs significantly increases IL-10 production.

Conclusion

These results indicate that K71 may alleviate UVB-induced skin barrier dysfunction by attenuating inflammation via increasing IL-10 production and that K71 RNAs may induce IL-10 production in macrophages. Therefore, K71 may be beneficial for preventing skin barrier dysfunction.     

Preparation of Low Free Gossypol and High Available Lysine Cottonseed/Soybean Blends

Cottonseed/soybean blends (50/50) were ground in an Alpine pin mill with or without previous cooking in a Brady low-cost extruder. Free gossypol decreased with increasing amount of water added prior to extrusion and number of passes through the extruder. Available lysine increased with decreasing amount of added water but was unaffected by number of passes through the extruder. Type of soybean raw material utilized had no effect on free gossypol. Blends prepared from defatted cottonseed meal, however, had lower free gossypol than those made from cottonseed kernels. A blend similar to full-fat soy flour but of lower cost was prepared from unextruded 50% defatted cotton-seed meal/50% extruded soybean flakes, without added water, and ground in the Alpine mill.     

ACEROLA's CLONES OF INDUSTRIAL INTEREST

In order to know which clone of acerola is better for acerola industrialization, we studied the pectin methylesterase (PME) specific activity, pectin content and vitamin C content in five different clones of acerola. The pectin yield varied from 1.37 to 2.99% and the highest content of pectin occurred in clones 3 and 5. Ascorbic acid varied significantly from 1157.5 to 1735.5 mg/100 g of pulp in the five clones. The highest content of vitamin C occurred in clone 4. The PME specific activity varied from 0.79 to 2.92 units g ^?1 /g of pulp and the highest values occurred in clone 2. We also studied the optimum temperature and the optimum pH of this enzyme. Clones 1, 2, 4 and 5 showed optimum temperature at 90C. Clone 3 showed practically the same specific activity at all temperatures studied. Clones 1 and 4 showed an optimum pH of 9.0 and clone numbers 2, 3 and 5 showed a pH optimum at 8.5.     

CHARACTERIZATION OF STOMACH AND PYLORIC CAECA PROTEINASES OF TAMBAQUI (COLOSSOMA MACROPOMUM)

The effects of pH, temperature, inhibitors, and substrates on proteolytic activities of crude extracts from the stomach, liver, pyloric caeca, and intestines of Colossoma macropomum were investigated. The highest acid and alkaline proteolytic activities were found in stomach and pyloric caeca, respectively. The optimum pH for the acid and alkaline proteases were 1.8 and 7.0–9.0, respectively, while the optimum temperatures were 35C and 65C. This alkaline protease thermal stability remained unaltered after 90 min incubation at 55C. A pepsin‐like protease was responsible for most of the acidic proteolytic activity (Pepstatin A inhibited approximately 90%), whereas PMSF inhibited about 40% of the alkaline protease. The alkaline proteolytic activity has attractive thermal properties for industrial applications.