EVALUATION OF THIN-LAYER DRYING MODELS FOR DESCRIBING DRYING KINETICS OF BARBERRIES (BARBERRIES VULGARIS)

Barberry is known as a medicinal and ornamental plant throughout the world. Edible fruit from the barberry is used in medicine to treat liver, neck and stomach cancer, for purification of the blood and for breath freshness. In order to assess and select a suitable form of the drying curve, six different semitheoretical and/or empirical models were fitted to the experimental data. Experiments were performed at air temperatures of 50, 60 and 70C. At each temperature, three air velocity values were selected: 0.5, 1 and 2 m/s. Consequently, of all the drying models, the Page model was selected as the best mathematical model according to R ², χ ² and root mean square error parameters. Constants related to the Page model are reported and regressed against air condition using multiple regression analysis.

PRACTICAL APPLICATION

All commercial flow dryers are designed on thin-layer drying principles. Thin-layer drying means to dry as one layer of sample particles or slices. In this paper we present a mathematical model for thin-layer drying of barberry fruits (moisture ratio against time). Definition of moisture ratio as a function of time and drying condition has many advantages such as (1) easy control of dryer system, (2) lower energy consumption, (3) less thermal damage to the products and (4) lower investment. It is believed that the present study should be useful to people seeking (1) to optimize the design of drying systems and their components, and (2) to identify appropriate applications and optimal configurations for drying systems.     

Production and evaluation of a probiotic yogurt using Lactobacillus casei ssp. casei

Skimmed milk was inoculated with the commercial starter and Lactobacillus casei ssp. casei. pH changes, viable counts, and organoleptic properties of the produced control and probiotic yogurts were analysed. The pH decrease during the fermentation period was faster in the milk inoculated with L. casei plus starter. The growth of both starters in probiotic yogurt was significantly lower than their growth in control yogurt during the fermentation period. The viable count of the probiotic bacterium remained higher than the standard limit for probiotic products. There was no significant difference between the organoleptic properties of the control and the probiotic yogurts.     

Superelastic properties of nanocrystalline NiTi shape memory alloy produced by thermomechanical processing

Effects of thermomechanical treatment of cold rolling followed by annealing on microstructure and superelastic behavior of the Ni₅₀Ti₅₀ shape memory alloy were studied. Several specimens were produced by copper boat vacuum induction melting. The homogenized specimens were hot rolled and annealed at 900 °C. Thereafter, annealed specimens were subjected to cold rolling with different thickness reductions up to 70%. Transmission electron microscopy revealed that the severe cold rolling led to the formation of a mixed microstructure consisting of nanocrystalline and amorphous phases in Ni₅₀Ti₅₀ alloy. After annealing at 400 °C for 1 h, the amorphous phase formed in the cold-rolled specimens was crystallized and a nanocrystalline structure formed. Results showed that with increasing thickness reduction during cold rolling, the recoverable strain of Ni₅₀Ti₅₀ alloy was increased during superelastic experiments such that the 70% cold rolled–annealed specimen exhibited about 12% of recoverable strain. Moreover, with increasing thickness reduction, the critical stress for stress-induced martensitic transformation was increased. It is noteworthy that in the 70% cold rolled–annealed specimen, the damping capacity was measured to be 28 J/cm³ that is significantly higher than that of commercial NiTi alloys.     

形变热处理制备的纳米晶NiTi形状记忆合金的超弹性行为（英文）

研究冷轧和后续退火形变热处理对Ni_(50)Ti_(50)形状记忆合金超弹性行为的影响。采用铜坩埚真空感应熔炼法制备样品。将成分均匀的样品进行热轧后在900°C退火,然后再进行冷轧,冷轧后样品的厚度有不同程度的减少,最大可达70%。透射电镜检测结果显示严重的冷轧导致Ni_(50)Ti_(50)合金中形成了纳米晶和非晶的复合显微组织。400°C下退火1 h后,冷轧样品中的非晶发生晶化形成纳米晶组织。随着冷轧变形量的增加,在超弹性实验中Ni_(50)Ti_(50)合金的弹性应变增加,变形量为70%的冷轧-退火样品其弹性应变为12%。此外,随着变形量的增加,应力诱导马氏体相变的临界应力提高。值得注意的是,70%变形量的冷轧-退火样品的阻尼容量值为28 J/cm3,明显高于商业NiTi合金。     

Delineating the role of phytocompounds against anti-bacterial drug resistance–An update

Antibacterial resistance developed by bacteria due to the unlimited use of antibiotics has posed a challenge for human civilization. This kind of problem is not limited to India only, but it is a global concern. Nowadays, many treatments and medicines for bacterial diseases have been developed. However, they possess some drawbacks. Therefore, the alternative medicine has been used to target the drug resistant mechanisms and such medicines have less side effects which is becoming necessary. Natural products have traditionally or historically been of importance for the development of antibacterial agents and are also known to overcome bacterial drug resistance by directly targeting the drug resistance mechanisms in bacteria. In recent years, researchers have also focused on new drug discovery from plant-based research. They have looked on various phytocompounds as antibacterial agents. In the current review, we report various classes of secondary metabolites such as phenolic compounds, flavonoids, alkaloids, saponins, terpenes, quinones, and some essential oils that have been used as an antibacterial agent. In addition, we also discuss several mechanisms behind bacterial multi-drug resistance that are used during bacterial pathogenesis.     

Fungal assembly of L-asparaginase using solid-state fermentation: a review

Because of its antitumor therapeutic-activity, as well as its application in food industries to improve the quality, L-asparaginase has attracted considerable attention from several investigators. In recent years, fungi have occupied advanced rank among microorganisms in the production process of the enzyme. This review is spotting the light on the advantages of fungal enzyme and its applications in the food industry and medications. The solid-state fermentation was discussed as the wide alternative and most accepted biosynthesis technique. However, some lights were also spotted to the statistical experimental design of the fermentation process, mainly on the methodology of the response surface for L-asparaginase biosynthesis by fungi. Finally, the immobilization of the enzyme and the features of the widely used solid substrates for the maximization of the production process were explored.     

Expression analysis of <i>OsSERK</i>, <i>OsLEC1</i> and <i>OsWOX4</i> genes in rice (<i>Oryza</i> sativa L.) callus during somatic embryo development

Somatic embryogenesis is an asexual reproduction process that occurs in many plant species, including rice. This process contains several totipotency markers such as Somatic Embryogenesis Receptor-like Kinase (SERK), Leafy Cotyledon1 (LEC1) and WUSCHEL-Related Homeobox4 (WOX4) and also a helpful model for embryo development and clones and transformations. Here, we report the gene expression during somatic embryo development correlates with regeneration frequency in 14 Javanica rice (pigmented and non-pigmented) using modifified N6 media supplemented with Kinetin (2.0 mg/L) and NAA (1.0 mg/L). Although there have been advances in understanding the genetic basis of somatic embryogenesis in other varieties, rice is still unexplored, especially during somatic embryo development. Moreover, for the formation of callus induction from immature embryos, 2,4-D (2.0 mg/L, 3.0 mg/L) was used. This study analysed the gene expression of OsSERK, OsWOX4 and OsLEC1 genes through RT-PCR analysis. Higher expression of the OsLEC1 gene indicates that their function may correlate in the in vitro with the high response of rice after transfer to regeneration media. This study found that rice varieties of pigmented rice (MS Pendek and Gogoniti II) and non-pigmented rice (Pandan Ungu) showed high regeneration frequency, showing higher OsLEC1 expression than other varieties because OsLEC1 promotes the maturation of somatic embryos in plant regeneration on day 14. However, the contrast with Genjah nganjuk may be effective because of other regulatory genes. RT-PCR analysis showed OsSERK had less expression level than OsLEC1 and OsWOX4 in the varieties, which correlate with the percentage of plant regeneration, but not for Gogoniti II. In conclusion, the higher percentage of plant regeneration correlates with the higher expression level of OsLEC1 at day 14 of media regeneration of rice.     

Changes in physicochemical and organoleptic properties of traditional Iranian cheese Lighvan during ripening

Lighvan cheese was studied to determine the physicochemical and biochemical changes over 90 days of ripening in brine. Acidity, pH, dry matter, fat values, lipolysis level, water‐soluble nitrogen (WSN), total nitrogen (TN), ripening index (RI), trichloroacetic acid‐soluble nitrogen (TCA‐SN) and organoleptic assessments were analysed. Dry matter and fat values decreased during ripening. Lipolysis level, RI, TCA‐SN values and salt content increased continuously until the end of the ripening period, but total nitrogen decreased throughout a 90‐day storage period. The ripening stage was the main factor affecting the cheese’s sensory properties.