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1993 - 199922000 - 20102
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Author: Sindhu, S × End date: 2012 × Type: Thesis ×
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    ThesisItemOpen Access
    Bioactivity of carotenoids from shrimp shell waste
    (Department of Processing Technology,College of Fisheries,Panangad, 2010) Sindhu, S; KAU; Sherief, P M
    Shrimp processing waste is the single largest industrial waste in the country causing diverse environmental problems. A study was carried out to assess the extractability of astaxanthin from shrimp waste in different organic solvents and vegetable oils. Extraction was tried using wet and dried waste, with and without deproteinisation. Waste was subjected to deproteinisation using alkali and enzyme (pancreatin). The different solvent systems tried were ether:acetone:water (15:75:10 v/v/v), acetone, hexane:isopropanol (3:2 v/v) and 90% acetone v/v. Astaxanthin in the extract was quantified by measuring the OD at 470 nm in hexane. Extraction was also done using vegetable oils viz. coconut oil, soybean oil and sunflower oil. Quantification of astaxanthin in pigmented oil was done by measuring the absorbance at 485 nm using 2155 as extinction coefficient. Astaxanthin yields from deproteinised samples were significantly lower than those from non deproteinised samples. The highest astaxanthin yield of 87.14 ± 4.55μg/g was obtained with non deproteinised wet waste extracted using acetone. The astaxanthin yield was significantly lower when oil was used as the extraction medium. Of the three oils coconut oil gave the highest yield. The results showed that acetone is the best solvent for extracting astaxanthin from shrimp shell waste in wet condition. The astaxanthin content in Aristeus alcocki shell waste is double that of Pandalus borealis shell waste, which is currently used as the commercial source of astaxanthin. The deep sea species Aristeus alcocki can thus be considered as a better source of astaxanthin for commercial exploitation than Pandalus borealis. TLC analysis of the shell waste extract showed that it contains free astaxanthin, astaxanthin monoester and astaxanthin diester in the ratio 1:1:2. GLC identification of the fatty acids esterified with astaxanthin revealed that saturated fatty acids, MUFA and PUFA are in the ratio 5:3:2 in monoester, whereas in diester they are in the ratio 4:3:3. The main fatty acids in monoester and diesters are palmitic acid, oleic acid, stearic acid and PUFAs: DHA and EPA. The in vitro antioxidant activity of the astaxanthin extract showed significant hydroxyl radical scavenging activity, superoxide anion scavenging activity and inhibition of lipid peroxidation. The IC50 values obtained were 56.43 ± 1.06 ng/ml, 27.91 ± 0.54 ng/ml and 26.54 ± 0.42 ng/ml, respectively. The antioxidant activity of astaxanthin from Aristeus alcocki was obtained at nanogram levels. This powerful antioxidant function may be due to the unique molecular structure of astaxanthin and synergistic effect of astaxanthin and PUFAs present in the astaxanthin monoester and diester fractions. The astaxanthin extract from shrimp shell waste significantly reduced carageenan induced paw edema in mice, percentage inhibition being 47.83 and 67.11 percent at astaxanthin concentrations of 0.5 mg/kg body weight and 1.0 mg/kg body weight, respectively. The inhibition of inflammation at 1.0mg/kg body weight was greater than that produced by the standard reference drug diclofenac. Cardioprotective effect of astaxanthin was examined in isoproterenol induced myocardial infarction in rats. Levels of diagnostic marker enzymes, LDH, CPK, GOT, GPT, CK, CK-MB in plasma, lipid peroxides, ascorbic acid, reduced glutathione and the activities of glutathione-dependent antioxidant enzymes GPx, GR, GST and antiperoxidate enzymes CAT, SOD and the membrane bound enzyme Na+ - K+ ATPase in the heart tissues of experimental groups of rats were determined. The prior administration of astaxanthin @ 10mg/kg feed for 45 days significantly prevented the isoproterenol-induced elevation in the levels of diagnostic marker enzymes in plasma, induction of lipid peroxidation and alterations in the level of reduced glutathione and in the activities of glutathione dependent antioxidant enzymes and antiperoxidative enzymes of experimental rats. Feeding astaxanthin caused a decrease in the inhibition of Na+ - K+ ATPase activity against isoproterenol induced myocardial infarction. The powerful cardioprotective effect of astaxanthin can be attributed to the multiple independent mechanisms viz. antioxidant effects, singlet oxygen quenching ability and inhibition of lipid peroxidation of membranes, increased functional gap junctional intercellular communication, anti-inflammatory effects etc. Immunostimulatory action of astaxanthin extract was evaluated in experimental mice. Astaxanthin administration was found to enhance the proliferation of spleen cells and bone marrow cells. Esterase activity was found to be enhanced in bone marrow cells indicating increased maturation of cells of lymophoid linkage. Astaxanthin also enhanced number of antibody forming cells and circulating antibody titre. Thus astaxanthin exhibits strong immunomodulating properties. A significant reduction in the viability of ascites tumour cells DLA in vitro was noted in the current study. The % viability was reduced to 4.34 % at a concentration of 15μg astaxanthin/ml. The cytotoxic action of astaxanthin against DLA may be through induction of apoptosis or through a different pathway. Antitumour activity of astaxanthin was studied by ascite and solid tumour models in mice. An increase in life span of about 67 % was noted in DLA bearing mice administered with astaxanthin at 5 mg/kg body weight. The tumour volume and tumour weight were significantly lower in mice injected with 5 mg/kg body weight astaxanthin. In vitro studies revealed that astaxanthin from shrimp shell waste of Aristeus alcocki inhibited the proliferation of cervical cancer cells HeLa in a dose dependent manner.
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    ThesisItemOpen Access
    Prospects and constraints of commercial cutflower production in Thiruvananthapuram district
    (Department of Agricultural Extension, College of Agriculture, Vellayani, 1997) Sindhu, S; KAU; Mothilal Nehru, S
    The present study under the title "Prospects and constraints of cutflower production in Thiruvananthapuram district" was undertaken with the following objectives. 1. To delineate the components of conceptual skill and to measure the conceptual skill of growers. 2. To study the relationship of personal, socio-situational and economic factors with the conceptual skill of growers. 3. To study the production practices of cutflowers followed by the growers. 4. To identify the different marketing channels existing in cutflower marketing in consultation with the growers. 5. To identify the constraints related to cutflower production and marketing as perceived by growers. The study was conducted among the respondents of five cutflower societies functioning in Thiruvananthapuram district. A sample of 100 growers were selected from the societies by adopting stratified random sampling technique with proportionate sampling procedure. Data was collected with the help of well structured, pre tested interview schedule and suitable statistical tests were employed in the analysis of data. In the study conceptual skill has been considered as dependent variable. The factors such as planning, risk-orientation, decision-taking ability, supervision and market perception were the major dimensions of conceptual skill. The selected personal, socio-situational and economic factors of cutflower growers were taken as independent variables which included education, cutflower growing experience, attitude towards cutflower growing, knowledge on cut flowers, self confidence, orientation towards competition, orientation towards skill development in farm workers, information seeking behaviour (personal), operational area, infra structural facilities, extension participation, social participation, mass media exposure (socio-situational), annual income and credit orientation (economic). Relationship of the personal, socio-situational and economic factors with the conceptual skill showed that in the case of Group I, none of the variables correlated with conceptual skill. In the case of Group 11 attitude towards cutflower growing, knowledge on cutflowers were positively and significantly correlated while mass media exposure was negatively and significantly correlated with conceptual skill. In the case of Group Ill, variables like cutflower growing experience, attitude towards cutflower growing, knowledge on cut flowers, orientation towards skill development and information seeking behaviour were correlated positively and significantly with conceptual skill. In the case of Group V a positive and significant relationship exists between conceptual skill and cutflower growing experience and orientation towards skill development in farm workers. In the case of Gr. V, a positive and significant relationship exists between conceptual skill and variables like cutflower growing experience, attitude towards cutflower growing, knowledge on cutflowers, self confidence, orientation towards skill development ill farm workers, information seeking behaviour and operational area. None of the socio-situational factors related significantly with conceptual skill of the respondents of Group I, Group 11, Group III and Group IV except for mass media exposure which was negatively and significantly correlated with conceptual skill of respondents of Group 11. None of the economic factors correlated with conceptual skill of the respondents of Group I, Group 11, Group Ill, Group IV and Group V. Regarding the production practices followed by anthurium growers, majority of growers have ordinary varieties. Majority of the growers follow pot planting using potting media containing sawdust, charcoal, brick and tile pieces, coconut husk and leaf-mould. Orchid growers have the collection of both monopodial and sympodial orchids and majority of the growers plant monopodial orchids in coconut husk alone and sympodial orchids in charcoal pieces alone. Regarding organic manure application, majority of the growers use diluted solution of fermented groundnut and neemcake in both the case of anthuriums and orchids. Majority of the growers apply 17: 17: 1 7 complex fertilizer solutions to both anthuriums and orchids. Majority of the growers apply organic manure and fertilisers once in a fortnight. Majority of the growers apply fungicides and pesticides once in a week regularly. Thus an indiscriminate use of fertilisers and plant protection chemicals was noticed in the study. Majority of the growers harvest flowers whenever there is demand. Flowers are cut during early mornings and late evenings. In the study various marketing channel ha been identified. in which the most important marketing channel of cutflowers identified was 'producer - collection centre - florishop- consumer'. Various production, technological and marketing constraints has been identified in the study. The important constraints perceived by the growers were 'high price of planting materials' (production), 'no standardised practices to follow' (technological) and 'inability of small growers to find market (marketing).
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    ThesisItemOpen Access
    Quality and shelf life of fillets and cubes of a marine perch (Lethrinus lentjan (Lacepede,1802)) smoked by a mechanical smoker
    (Department of Processing Technology, College of Fisheries, Panangad, 2004) Sindhu, S; KAU; Krishnakumar, S
    A study was undertaken for the preparation of cubes and fillets from a marine perch King emperor or Pig face bream (Lethrinus lentjan, (Lacepede), 1802)). A method was standardised for preparation of smoked cubes and fillets. The parameters standardised were brining conditions, draining conditions, pre-drying conditions, smoking temperature and smoking time. The various brining conditions studied were brine concentrations of 10 %, 15 % and 20 % for brining times 15 min, 30 min and 45 min each. The various draining conditions studied were draining at room temperature and refrigerated conditions for periods of 15 min, 30 nun and 45 min. The pre drying conditions studied were pre-drying in tray drier and smoking kiln at 500e for 15 min, 30 min and 60 min. The smoking conditions studied were smoking at temperatures of so'c, 90oe, 1 oo'r: for 1 hr, 2 hrs and 3 hrs each. Salt content, moisture content and phenol content of the samples were analysed based on parameters studied in addition to sensory evaluation. Based on the test results the following treatments were selected viz., brine concentration of 10 % and brining time 15 min, draining under refrigerated condition for 30 min, pre-drying in tray drier for 30 min at 500e and smoking temperature of 800e for a period of 3 hrs. Smoked cubes and fillets were prepared using the standardised procedure and subjected to storage studies for a period of four months under different packing conditions viz., (i) smoked cubes and fillets packed in PE bags (ii) smoked cubes and fillets dried at 500e for 1 hr and then packed in PE bags and (iii) smoked tubes and fillets dried at 500e for I hr and then packed in paper bags. Quality changes during the storage period were monitored 15 days time intervals for parameters viz., moisture content, per cent free fatty acids, thio barbituric acid value, total plate count, total fungal count and sensory evaluation. Samples packed in paper bags remained acceptable only up to 60 days of storage and samples packed in PE bags were acceptable upto 90 days of storage.
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    ThesisItemOpen Access
    Interspecific cross- compatibility in the genus Abelmoschus
    (Department of Plant Breeding, College of Agriculture, Vellayani, 1993) Sindhu, S; KAU; Manikantan Nair, P
    Interspecific cross – compatibility in the genus Abelmoschus was undertaken with the objective of probing into the reasons of low fruit and seed set in the interspecifc hybrids of Abelmoschus which may pave the way for the development of yellow vein mosaic resistant varieties through recombination breeding. Crossing was done between the local cultivar Abelmoschus esculentus var. Anacomban and two semi wild species (A. manihot and A. manihot ssp. Tetraphyllus). The fruit set in direct crosses of A. esculentus var. Anacomban x A. manihot and A. esculentus var. Anacomban x A. manihot ssp. Tetraphyllus was very low compared to the reciprocal crosses, exhibiting partial incompatibility consequent on the slow pollen tube growth of A. manihot and A. manihot ssp. tetraphyllus. The seed set was low in crossed fruits and there was recovery of shriveled seeds which may be attributed to the poor endosperm development. The crossed seeds exhibited good viability. All the hybrids exhibited field tolerance to yellow vein mosaic disease. The four hybrids recorded pollen sterility which may be attributed to meiotic abnormalities, due to difference in chromosome number between the species. The seed set in the hybrids was very low. The seed set was inversely proportional to pollen sterility. The lower the pollen sterility higher was the seed set. The F2 seeds showed reduction in seed weight which may be due to high seed sterility exhibited by the hybrids. The recovery of empty seeds which appeared normal may be ascribed to endosperm degeneration. The seed viability of F2 seeds was very low. The result leads to the conclusion that the reason for low fruit and seed set in interspecific hybridization in Abelmoschus may be due to partial incompatibility. The interspecific hybrids displayed hybrid sterility which may be attributed to the meiotic abnormalities consequent on the difference in the chromosome number between the parents. However, all the hybrids were not completely sterile. The hybrids exhibited field tolerance to yellow vein mosaic disease which is an added advantage. Back crossing the F1 as the seed parent to the A. esculentus var. Anacomban may overcome the hybrid sterility and pave way for the development of varieties with yellow vein mosaic resistance coupled with economic attributes of the popular cultivar Anacomban.