Comparative Study on the Influence of Various Drying Techniques on Drying Characteristics and Physicochemical Quality of Garlic Slices.

Effects of vacuum freeze drying (VFD), air impingement drying (AID), hot air drying based on temperature and humidity control (TH-HAD), pulsed vacuum drying (PVD), and medium- and short-wave infrared radiation drying (MSIRD) on the drying characteristics and physicochemical properties of garlic slices were investigated in the current work. Based on the experimental results, the Weibull model fitted the experimental results better (R2 > 0.99) than the Wang and Singh model. Samples dried with PVD showed the smallest color difference (ΔE*), better rehydration capacity and desirable reducing sugar content. In response to thermal effects and pressure pulsations, the cell walls gradually degraded, and the cell and organelle membranes ruptured. The allicin and soluble pectin contents of garlic slices treated with PVD were higher by 8.0-252.3% and 49.5-92.2%, respectively, compared to those of the samples dried by other techniques. VFD maintained a complete garlic slice structure with the minimum shrinkage and the best appearance. The MSIRD process produced the densest structure, and caused an additional loss of color and phytochemical contents. The findings in current work implied that PVD could be a promising drying technique for garlic slices.

Pulsed Vacuum Drying of Persimmon Slices: Drying Kinetics, Physicochemical Properties, Microstructure and Antioxidant Capacity.

In order to explore an alternative drying method to enhance the drying process and quality of persimmon slices, pulsed vacuum drying (PVD) was employed and the effects of different drying temperatures (60, 65, 70, and 75 °C) on drying kinetics, color, rehydration ratio (RR), microstructure, bioactive compounds, and the antioxidant capacity of sliced persimmons were investigated in the current work. Results showed that the rehydration ratio (RR) of the samples under PVD was significantly higher than that of the traditional hot air-dried ones. Compared to the fresh samples, the dried persimmon slices indicated a decrease in the bioactive compounds and antioxidant capacity. The total phenolic content (TPC) of PVD samples at 70 °C was 87.96% higher than that of the hot air-dried persimmon slices at 65 °C. Interestingly, at 70 °C, the soluble tannin content and TPC of the PVD samples reached the maximum values of 6.09 and 6.97 mg GAE/g, respectively. The findings in the current work indicate that PVD is a promising drying method for persimmon slices as it not only enhances the drying process but also the quality attributes.

The effect of high humidity hot air impingement blanching on the changes in cell wall polysaccharides and phytochemicals of okra pods.

BACKGROUND: Okra pods contain heat-sensitive substances, such as phenolic compounds and other phytochemicals that can be degraded when okra pods are subjected to heat treatment. The understanding of the impact of high humidity hot air impingement blanching (HHAIB) on the changes in physicochemical properties of polysaccharides and phytochemicals of okra pods is of great importance because over-blanching may result in cell membrane disruption and changes in biologically active compounds under prolonged exposure to the thermal treatment. Therefore, the present study aimed to investigate the effect of HHAIB on the changes in physicochemical properties of pectins and phytochemicals extracted from okra pods. RESULTS: Both the HHAIB time and method of extraction influenced their physicochemical characteristics and biological activity. Pectin fractions subjected to HHAIB were composed of polygalacturonic acid, rhamnogalacturonan, glucomannan, galactan, mannose, arabinose, rhamnose, calcium pectate and arabinogalactan. The contents of total phenolics, total flavonoids and antioxidant activity of extracts mostly increased during HHAIB (i.e. up to 19.0%, 13.2% and 35.3%, respectively). However, HHAIB reduced the chlorophyll-a (up to 55.7%) and lycopene (up to 52.6%) contents of okra pods. CONCLUSION: The acquired knowledge may be useful for better understanding and optimization of technologies based on HHAIB treatment. The HHAIB treated okra can be a promising natural alternative in different applications, including its use as a replacement of some ingredients in food or non-food systems as a result of richness in polysaccharides and polyphenols, as well as high antioxidant properties. © 2022 Society of Chemical Industry.

Effects of ripening stage on physicochemical properties, drying kinetics, pectin polysaccharides contents and nanostructure of apricots.

Effects of ripeness (four stages from the lowest to highest degree-I, II, III, and IV) on the physicochemical properties, pectin contents and nanostructure, and drying kinetics of apricots were investigated. The color values (L*, a*, and b*) and total soluble solid content increased during ripening, while the titratable acidity content and hardness decreased. The water-soluble pectin content increased as ripening progressed, but the chelate- and sodium carbonate-soluble pectin contents gradually declined. Atomic force microscopy imaging indicated that the pectin depolymerization occurred during ripening. Fruits at stage III obtained the highest drying rate, and the drying time was reduced by 27.27%, 17.24%, and 7.69% compared to those of stage I, II and IV, respectively. Results showed that the ripeness had significant influence on the drying kinetics, which is related to the modification of physicochemical and pectic properties. The ripeness classification is an essential operation for achieving effective drying process.

[Impact of Salinity on Leachate Treatment and N2O Releases from Semi-aerobic Aged-refuse Bioreactor].

Semi-aerobic Aged-refuse Bioreactor (SAARB) has a good effect on nitrogen removal in leachate, but a strong greenhouse gas (N2O) was generated during the nitrification and denitrification process. The effect of salinity (7-30 g x L(-1)) on the leachate treatment and the N2O production from SAARB system was investigated. Experimental results showed that salinity ranging from 7 to 30 g x L(-1) had no significant effect on COD removal, and the removal efficiency was always more than 85%. On the contrary, it had a strong influence on the removal of nitrogen. The removal efficiencies of NH4+ -N and TN decreased from 98. 23% and 91.48% at 7 g x L(-1) salt to 31.75% and 34.24% at 30 g x L(-1) salt, respectively. Moreover, there was significant nitrite (NO2- -N) accumulation in the presence of 30 g x L(-1) salt. Meanwhile, salinity had different inhibition strength on nitrification and denitrification bacteria, and the order of inhibition strength was as follows: nitrification bacteria > denitrification bacteria. In addition, the N2O production increased with salinity concentration, and the highest N2O accumulation (1397 microg +/- 369.88 microg) was observed with addition of 30 g x L(-1) salt, which accounted for 8.87%o of the total nitrogen removal. Meanwhile, it was 6-117 times higher in the presence of 30 g x L(-1) salt than that in low salinity conditions (7-20 g x L(-1)). And the peak time of the N2O production showed a delayed trend. These results indicated that salinity recirculation in leachate had a negative effect on the nitrogen removal and N2O production. Overall, salinity seemed to be a key parameter during leachate recirculation.

[Analysis on Diversity of Denitrifying Microorganisms in Sequential Batch Bioreactor Landfill].

A denitrification functional microorganism gene clone library (amoA, nosZ) and the PCR-RFLP technology was constructed to investigate the microbial diversity of denitrifying microorganisms in the late period of stabilization of sequential batch bioreactor landfill. The results indicated that: the bacterial diversity of ammonia oxidizing bacteria in the aged refuse reactor was very high, and most of them were unknown groups, also, all bacteria were unculturable or had not been isolated. The phylogenetic analysis suggested that the dominant ammonia oxidizing bacteria were presumably Nitrosomonas of 6-Proteobacteria. The diversity of denitrifying bacteria in fresh refuse reactor was abundant, which mainly included Thauera and Thiobacillus of 6-Proteobacteria. As Thauera sp. has the denitrification characteristics under the condition of aerobic while Thiobacillus denitrificans has the autotrophic denitrification characteristics, it was speculated that aerobic denitrification and autotrophic denitrification might be the main pathways for nitrogen removal in the fresh refuse reactor at the late period of stabilization. Additionally, another group in the gene clone library of denitrifying bacteria may be classified as Bradyrhizobiaceae of alpha-Proteobacteria.

Association between RAD51 polymorphism and breast cancer susceptibility: a meta analysis.

BACKGROUND: RAD51 interacting with BRCA1 and BRCA2 could modulate the penetrance of BRCA1/BRCA2 mutations, which may increase susceptibility for breast cancer by inhibiting DNA repair and genome stability. The purpose of this study was to provide refined statistical evidence for the association between RAD51 polymorphism and breast cancer risk. DESIGN AND RESULTS: We conducted a meta-analysis of 15 publications with a total of 11,766 cancer cases and 11,227 controls. We summarized the data on the association of RAD51 polymorphism with breast cancer risk and performed subgroup analyses by ethnicity and control source. The pooled ORs based on fixed-effects model did not indicate a modified risk of breast cancer associated with RAD51 polymorphism in the overall population. Nor did we find a significant association in any stratified analysis. CONCLUSIONS: This meta-analysis suggested that RAD51 polymorphism did not appear to represent a significant risk factor for breast cancer.

[Studies on hypoglycemic effect of extract of Balaophora polyandra in mice].

OBJECTIVE: To study the hypoglycemic effect of the extract of B. polyandra (SHG). METHOD: The diabetic mice were induced by alloxan in ICR mice. The blood glucose concentration was measured by glucose oxidase method. The serum insulin level was determined by 125I-insulin radioimmunoassay kit. The hypoglycemic effect was evaluated by the levels of both fasting and no-fasting blood glucose. The effect on serum insulin level was estimated by the values of the blood insulin and the changes of the blood glucose induced by the glucose intraperitoneal injection. The effect on the glucose absorption was investigated by the oral sucrose or starch tolerance test. RESULT: Both of the fasting and no-fasting blood glucose levels were decreased significantly by the treatment of 20 or 30 g raw materials crude drug x kg (-1) SHG orally for 7-10 d in ICR mice or in alloxan diabetic mice. In the oral sucrose tolerance test or oral starch tolerance test, the administration of SHG reduced significantly the peak value of the blood glucose and the area under the blood glucose-time curve (AUC) in normal or alloxan diabetic mice, respectively. These effects of SHG were similar to those of acarbose, a kind of alpha-glucosidase inhibitors. In the oral glucose tolerance test in normal and alloxan diabetic mice, SHG decreased both the blood glucose peak and the AUC induced by the glucose loading. But in the intraperitoneal injection glucose tolerance test the levels of insulin in both SHG and control mice were similar, however, the changes of the blood glucose level after the glucose-loading for 30 min in SHG mice was much lower than that in control mice. CONCLUSION: With the treatment of SHG, the fasting and no-fasting blood glucose concentrations were decreased and the glucose tolerance improved significantly in both normal and alloxan diabetic mice, and the inhibition of a-glucosidase might be one of its major mechanisms.