Browsing by Author "Saravanan Raju"
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ThesisItem Open Access Investigaiton on extraction of starch from cassava (Manihot esculenta Crantz) stem(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2019) Hasmi Sulain, K K; KAU; Saravanan RajuThe study entitled “Investigation on extraction of starch from cassava (Manihot esculenta Crantz) stem” was carried out at the Division of Crop Utilization, ICAR- Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram during the year 2018- 2019. Cassava stem starch is an ideal source to increase the availability of starch without using additional land, water and fertilizers. Hence understanding the structural and functional properties of stem starch is an important aspect before substituting with root starch because there is a lack of knowledge of starch properties when compared to root starch. In this study, starch from cassava stem were extracted by four different methods such as extraction using water, extraction using chemicals such as Sodium hydroxide and sodium meta bi sulphate, microwave assisted extraction and ultra sound assisted extraction. The cassava genotypes suitable for extraction of starch from stem and functional properties of this stem starches were investigated. In the present study, the physiological characters of such as stem length, stem girth, stem fresh weight and stem dry weight and stem moisture content were measured in the selected genotypes of cassava. The results showed that stem length of cassava ranges from 100-300cm and the stem girth ranges from 2.5-8cm. The fresh weight and dry weight of cassava stem ranges from 0.4-2Kg and 0.2-0.7Kg respectively.The moisture content of cassava stem varies from 62-72% but the moisture content was less than 2% in all stem starches. The swelling volume was same for all the stem starches (15ml) and the solubility was less than 10%. Starches with high swelling volume and solubility and low gelatinization temperature has various applications in food industry. The water binding capacity varied from 46.09% to 77.50% for different cassava stem starches. The in vitro starch digestibility of cassava stem starches ranges from 0.1-0.3 g/g. The starch yield from cassava stem ranges from 17% to 30% and the starch content was found to be 38-55% on dry weight basis. The starch yield was found to be maximum for H-1687 and minimum for Quintal. 64 The peroxidase content in cassava stem starches ranges from 0.05-0.13ng/mg and the poly phenol oxidase content ranges from 10-30mg/g. Both this enzyme content was found to be lowest in Black Thailand and maximum for Sree Swarna and Quintal. It was found that extraction using ultra sound and micro wave assistance could increase the extractability of starch from cassava stem and the genotypes H1687 and H-226 was found to be high starch yielding varieties and thus it could be used for the extraction of starch from cassava stem. Cassava stem contain more than 30% of starch (dry mass), hence the wasted cassava stem starch can be utilized for both food and non-food applications. More over cassava can increase both food and fuel resources where cassava roots are for food and stems for fuel and even reduce poverty without using additional land.ThesisItem Open Access Investigations on nutritional aspects of Cassava (Manihot esculenta Crantz) Leaf and its enrichment(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2019) Reshma, A; KAU; Saravanan RajuThe study entitled “Investigations on nutritional aspects of cassava (Manihot esculenta Crantz) leaf and its enrichment” was carried out at the Division of Crop Utilization, ICAR – Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram during the year 2018 – 2019. Cassava (Manihot esculenta Crantz) is a major stable food crop for sustainable agricultural practice and food security in both developing and under developed countries. Cassava leaves are rich in protein, carotenes, vitamins B1, B2, and C, and minerals such as calcium, magnesium and also rich in anti-nutritional factors such as cyanogens. Efficient use of cassava products resulted in reduced feed costs. With proper processing the inclusion levels of cassava leaves in diets can be increased and can be used as an alternative energy source. The total fresh weight and dry weight (in grams), and number of leaves (per plant) were studied. For the ten different genotypes the fresh weight and dry weight of the leaves ranged from 168.33 g – 398.77 g plant-1 and 129.67 to 44.57 g plant-1. The number of leaves per plant also varied greatly in number per plant of each genotypes. The crude fibre content of the leaves ranged from 6.4 to 10.3% (Oke, 1966). In the present study the fibre content of leaves was obtained ranging from 18.73 to 48.67% for different genotypes. The lignin content in cassava leaves determines its anti nutritional quality. Higher content of lignin in feed limits its consumption. The lignin content obtained from the study ranges from 0.06 – 0.15 g/g for different genotypes. The linamarin content present in the leaves of the ten cassava genotypes were analysed and it ranged from 0.75 to 6.04 mg g-1 on a fresh weight basis. On a dry weight basis the content ranges from 0.34 to 1.2 mg g-1. The linamarin content at 7th day and 20th day of enrichment of the genotypes H1687 was found to be 0.3549 and 0.3504 mg g-1 while for the genotype Malayan 4 it was found to be 0.3631 and 0.355 mgg-1 respectively. The content can be reduced greatly as the duration of fermentation increases. The rapid reduction in the level of cyanide 75 after ensiling implies that ensiling is an effective way of reducing HCN in cassava leaves and roots before feeding them to dairy animals. In the present study, different genotypes of cassava leaves showed that the content of trypsin inhibitors reaches up to a maximum value of 33.41% for the genotype Sree Jaya (three month old plants). The protein content of the cassava leaves was found to be higher in all genotypes. The protein content of the enriched samples was found to be reduced at 7th day and 20th day when compared to the samples at 0th day. Addition of additives such as molasses resulted in reduction of protein content in the silage, The presence of high content of mineral elements particularly Ca, Mg, K elements in cassava leaves confirms its importance as a rich source of mineral elements. The mineral elements Cu, Zn, Fe, Mn, P present in leaves ranges between 24.7 to 29.7 (mg/L), 123.2 to 230.9 (mg/L), 420 (mg/L) to 476.7 (mg/L), 151.3 (mg/L) – 385.9 (mg/L) and 1.53395 (mg/L) -2.9466 (mg/L) respectively. The mineral elements was found to have a slight decrease in the content on enrichment at 7th and 20th day when compared to initial days. For the present study urea was added as N source, yeast and molasses are also added into the silage for the enrichment purposes which enhance the fermentation rate of the silage that resulted in a characteristic odour, flavour and colour of the silage. The H1687 and Malayan 4 (M4) genotypes having high dry matter and protein content is suitable for use as leaf meal and preparation of silage from cassava leaves.ThesisItem Open Access Physiological and molecular studies on cyanogenic potential in cassava (Manihot esculenta Crantz) in response to nitrogen nutrition, water stress and shade(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2018) Achuth, P. Jayaraj; KAU; Saravanan RajuThe study entitled “Physiological and molecular studies on cyanogenic potential in cassava (Manihot esculenta Crantz) in response to nitrogen nutrition, water stress and shade” was carried out at the Division of Crop utilization, ICAR- Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram during the year 2017-2018. To study the physiology and molecular aspects of biosynthesis of cyanogenic glycosides in cassava in response to plant nitrogen status, light intensity and water stress and to compare detection methods such as Near-infra red (NIR) spectroscopy and High Performance Thin Layer Chromatography (HPTLC) for cyanogenic glycoside estimation. Cassava (Manihot esculenta Crantz) contains cyanogenic glycosides like linamarin, acetone cyanohydrin, and hydrocyanic acid. The concentration of cyanogens in roots and leaves differ in the same plant and is known to be more abundant in the leaves than the stem and roots. The synthesis and regulation of bioactive natural products are influenced by changes in the nutritional availability of both micro and macro. It is important to be aware of and understand the consequences of such changes so that appropriate measures can be taken to either reduce risks or capitalize on benefits. Here in this study not much difference was observed between plants grown in shade irrigated and open irrigated in level of CNglc content. Plants grown in shade water stress have CNglc amount at par with plants grown in open water stress. Increased nitrogen supply stimulates plant growth and productivity as well as photosynthetic capacity of leaves through increased amounts of stromal and thylakoid proteins in leaves. Here CNglc content increase according to nitrogen nutrition doesn’t seems to follow a uniform pattern as in case of Sree Vijaya CNglc content remains unchanged or a small decrease is seen. Also here although an increase is seen in CNglc content from 0.5x to 1x strength, increase is not seen in 2x strength solution. Detection of CNglc in plant samples are important for not only quality control but for many other aspects of biochemical research. Various techniques are used for estimating CNglc in cassava samples and the enzymatic and spectro-photometric techniques are routinely used. From this study NIR data and HPTLC data obtained from this investigation can be used for developing methods for quantifying the CNglc content directly in plant samples in the future without cumbersome sample preparation techniques.