Browsing by Author "Aswathy Rajan"

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    Development and quality evaluation of bitter gourd (Momordica charantia L.) based low calorie dietetic beverages
    (Department of home science, College of horticulture, Vellanikkara, 2014) Aswathy Rajan; Seeja Thomachan Panjikkaran
    Bitter gourd occupies a prominent position among the vegetables grown in India. The importance of bitter gourd has long been recognized due to its nutritive value and medicinal properties. It contains a unique phytoconstituent namely charantin that has been confirmed to have hypoglycemic effect. There is also an insulin like compound known as polypeptide P which has been recommended as an insulin replacer in diabetic patients. The present study entitled “Development and quality evaluation of bitter gourd (Momordica charantia L.) based low calorie dietetic beverages” was aimed to standardise low calorie bitter gourd based dietetic beverages and to evaluate the chemical, nutritional, organoleptic and shelf life qualities of the products. Standardisation of RTS beverages from bitter gourd and its blend with ash gourd was carried out in 18 treatments. Sugar, low calorie sweetener and salt based beverages were tried. For flavouring, cardamom and ginger drops were used. Based on organoleptic evaluation, the most acceptable beverages ie., two each from sugar based, low calorie sweetener based and salt based were selected for storage study. Thus, twelve beverages were selected. The selected beverages were prepared and stored for three months at ambient and refrigerated conditions. Organoleptic qualities, chemical constituents and shelf life qualities were evaluated initially and monthly intervals for a period of three months. The β carotene and total phenol content in RTS beverages showed a significant difference during ambient and refrigerated storage whereas the variation observed in total soluble solids (TSS), total sugar, reducing sugar and vitamin C content was statistically insignificant. The acidity of RTS beverages increased during storage at ambient condition, but a decreasing trend was noticed under refrigerated condition. The loss of ascorbic acid was more in beverages stored under ambient condition, compared to RTS beverages stored in refrigerated condition. The phenol content was found to be low in RTS beverages prepared by blending bitter gourd and ash gourd juice. The duration and conditions of storage had no influence on the mineral constituents of the beverages. The beverage prepared with equal quantity of bitter gourd and ash gourd juice with salt and one drop of cardamom was found to be nutritionally superior when stored under refrigerated condition. A gradual decrease in organoleptic qualities of the beverages like appearance, colour, flavour, taste and overall acceptability was noticed during storage. The RTS beverage prepared using bitter gourd and sugar attained maximum mean scores followed by beverages prepared with bitter gourd juice + low calorie sweetener and bitter gourd juice + sugar and flavoured with cardamom drops. The same trend was observed under both storage conditions. The bitter gourd based dietetic RTS beverages were evaluated initially and at monthly intervals for bacteria, yeast and fungi for a period of three months. Yeast and fungi were not detected in any of the beverages throughout the storage period. At the end of third month of storage the presence of bacteria was observed in all the treatments stored under ambient and refrigerated conditions, but they have not exceeded the permissible threshold levels of microbial population. The RTS prepared with bitter gourd and sugar was found to be the best in organoleptic evaluation and consumer acceptance studies. Blending of bitter gourd juice with ash gourd juice and flavouring with spice drops improved the nutritional as well as organoleptic qualities of RTS beverages. To increase the consumption of bitter gourd as an anti diabetic vegetable, production of RTS beverage is a viable technology and it has ample scope for commercial exploitation.
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    Expression profiling of microRNAs associated with virus infection in banana cultivar red banana (Musa AAA)
    (Department of Plant Biotechnology, College of Agriculture, Vellayani, 2020) Aswathy Rajan; Soni, K B
    The study entitled “Expression profiling of microRNAs associated with virus infection in banana cultivar Red Banana (Musa AAA)” was conducted at the Department of Plant Biotechnology, College of Agriculture, Vellayani, Thiruvananthapuram during 2018-2020. The objective was to study the expression of selected miRNAs in Banana bract mosaic virus (BBrMV) and Banana bunchy top virus (BBTV) infection in banana cultivar Red Banana (Musa AAA). In a study conducted in the Department of Plant Biotechnology, 52 mature miRNAs were predicted using NovoMIR software and over 142 targets were identified for these miRNAs using psRNATarget in the banana genome. On validation of these miRNAs, Subramanian (2019) found differential expression of a few of them in tissue culture grown banana var. Nendran infected with BBrMV. In this study, two of those miRNAs and their target genes i.e. miR-6928-5p (target: Flavin adenine dinucleotide dependent oxidoreductase gene) and miR-971-5p (target: Argonaute protein) were studied for their expression in field infected samples. Banana plants of cultivar red banana infected with BBrMV and BBTV were collected from the Instructional Farm, College of Agriculture, Vellayani, based on the visual symptoms. The BBrMV and BBTV infections were reconfirmed by PCR using the primers specific to coat protein genes of the viruses. All the infected samples showed the presence of specific amplicons of the expected size (745bp) compared to the uninfected samples. RNA isolated from the leaf samples of both control and infected plants were reverse transcribed to cDNA. The PCR analysis confirmed the presence of both miRNAs and their target genes in the banana samples. The expression analysis conducted by RT-qPCR showed differential expression of miR-6928-5p and miR-971-5p in BBrMV and BBTV infected plants. In BBrMV infected samples, miR-6928-5p was downregulated up to 0.01 fold and the BBTV infected samples showed an upregulation of this miRNA up to11.08 fold. The mRNA transcript encoding FAD dependent oxidoreductase showed downregulation in BBrMV infected samples (upto 0.43 fold) and in BBTV infected samples the change was marginal. But within the infected plants both miRNA and its target showed an inverse correlation. miR-971-5p was found to be down regulated in both BBrMV and BBTV infected samples (a maximum of 0.21 and 0.17 fold respectively). On the other hand, its target mRNA transcript encoding Argonaute protein showed a maximum of 3.09 and 1.89 fold increase in the BBrMV and BBTV infected samples. Here both miR-971-5p and its target gene showed an inverse correlation in their expression in both BBrMV and BBTV infection. The study showed that both miR-6928-5p and miR-971-5p respond to BBTV and BBrMV infection in banana cultivar red banana (Musa AAA).