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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Jackfruit (Artocarpus heterophyllus Lam.) as a potential source of bioactive compounds(Department of Post Harvest Technology, College of Agriculture, Vellayani, 2022) Viresh; KAU; Mini, CAn investigation on “Jackfruit (Artocarpus heterophyllus Lam.) as a potential source of bioactive compounds” was carried out at Department of Post Harvest Technology, College of Agriculture, Vellayani from 2017-2020 with the objectives to standardize the extraction procedure for maximizing the antioxidant, anti-cancerous and anti-hyperglycemic properties of fruit wastes from varikka and koozha jackfruit types, phytochemical profiling, encapsulation and commercial exploitation of encapsulated extracts for fortification of fruit juice beverages. Experiments were carried out in four parts. Standardization of extraction procedure was carried out in the first part by evaluating the extracts for antioxidant, anti-hyperglycemic and anti-cancerous properties. Both varikka and koozha types were harvested at optimum maturity and were utilized at ripe stage independently. Except bulb, seed and peel without horny portion, all other parts were dried in cabinet (D1) and freeze (D2) driers, pulverized to fine powders and extracts were prepared using solvents viz., methanol at 90 (S1), 80 (S2), 50% (S3) and ethanol at 60 (S4), 80 % (S5) with solid to solvent ratios of 1:30 (R1), 1:40 (R2) and 1:50 (R3). Extract of freeze dried varikka samples using 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3) had highest Total flavonoid content (TFC) (15.66 mg QE 100g-1 ), Total phenolic content (TPC) (156.10 mg GAE 100g), DPPH scavenging activity (69.29 per cent inhibition) and α-glucosidase inhibition activity (90.24 per cent). The same extract, D2S4R3 from koozha also exhibited highest TFC (15.88 mg QE 100 g -1 ), TPC (164.63 mg GAE 100g), DPPH scavenging activity (68.64 per cent inhibition) and α-glucosidase inhibition activity (92.28 per cent). Freeze dried varikka samples extracted using 90 per cent methanol at 1:50 solid solvent ratio (D2S1R3) recorded the highest (45.88 mg 100g-1 ) ascorbic acid content and freeze dried koozha samples extracted using 90% methanol at 1:40 solid solvent ratio (D2S1R2) had the highest ascorbic acid content of 47.37 mg 100g-1 . 310 Based on the efficiency and economics, extraction of freeze dried samples using 60% ethanol at 1:40 solid to solvent ratio (D2S4R2), similar samples using 60% ethanol at 1:50 solid to solvent ratio (D2S4R3 ) and cabinet dried samples with 60% ethanol at 1:50 solid to solvent ratio (D1S4R3) were selected as three superior extraction methods . The MTT system which is a simple, reproducible and accurate means of measuring the activity of living cells via mitochondrial dehydrogenases was utilized to assess the anti-cancerous properties of the selected three extracts viz., D2S4R2, D2S4R3 and D1S4R3 on HeLa cell lines with doxorubicin as control. Freeze dried varikka and koozha samples extracted in 60 percent ethanol at 1:50 solid to solvent ratio (D2S4R3) had the lowest IC50 value of 129.30 and 157.60 µg mL-1 respectively whereas the IC50 value for doxorubicin (positive control) was18.85 µg mL-1 . When the three superior extracts were subjected to phytochemical profiling in the second part of the experiment using LCMS/MS (Waters UPLC H class system fitted with TQD MS/MS system) for sugars, organic acids, phenolic acids and flavonoids, they were significantly influenced by extraction methods and jack fruit types. Fifteen sugars, ten organic acids, eighteen phenolic acids and fifteen flavonoids were fractionated and identified from the extracts. Extract of freeze dried sample using 60% ethanol in 1:50 solid to solvent ratio (D2S4R3) had highest sugars, organic acids, phenolic acids and flavonoid content. The major sugars identified were fructose, glucose, mannose, sucrose and sorbitol and; organic acids were citric acid, malic acid, shikimic acid, succinic and hydroxycitric acid; phenolic acids were ferulic acid, p-coumaric acid, caffeic acid, benzoic acid, o - coumaric acid; myricetin, catechin, naringenin, quercetin and epicatechin were the major flavonoids. The three superior extracts selected were encapsulated independently by spray and freeze drying in the third part of the study. Two maltodextrin (MD) levels (10 and 20 dextrose equivalence, DE), three carrier to extract ratio (1:10, 1:15 and 1:20), two inlet- outlet temperature of spray drier (180 - 80º C inlet - 311 outlet and 190 - 90º C inlet - outlet) were the process variables for spray encapsulation, whereas for freeze encapsulation, maltodextrin (MD) levels and carrier ratio were selected as process variables. The extract D2S4R3 from varikka and koozha, spray encapsulated using MD 20 DE at 1:20 carrier to extract ratio (Cr3) at inlet and outlet temperature of 180 and 80º C (T1) recorded highest TPC of 115.47 and 117.92 mg GAE 100 g-1 respectively. Varikka and koozha extracts spray encapsulated using MD 20 DE at 1:10 carrier to extract ratio at 190 - 90ºC inlet - outlet temperature (C2Cr1T2) produced encapsulate with highest per cent recovery (83.77 and 82.09 % respectively). Lowest moisture content of 2.46 and 2.55 per cent were recorded by the extracts spray encapsulated using 10 DE MD at 1:20 carrier to extract ratio at inlet - outlet temperature of 190 - 90º C (C1Cr3T2) from varikka and koozha respectively. Based on the superior physico-chemical properties, spray encapsulate of freeze dried varikka and koozha extracts prepared using 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3), using 20 DE maltodextrin at 1:20 carrier to extract ratio with 180 - 80°C inlet - outlet temperature (C2T1Cr3), was selected for Part 4 of the experiment. D2S4R3 extract from varikka and koozha, when freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio had highest TFC of 11.62 and 11.75 mg QE 100 g-1 respectively. Koozha extract, freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio had highest TPC of 134.38 mg GAE 100 g-1 DPPH scavenging activity of varikka and koozha extracts were highest when freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio (per cent inhibition of 71.66 and 77.48 respectively). Ascorbic acid content and per cent recovery of encapsulates were not influenced by levels of MD or carrier to extract ratio. The extracts freeze encapsulated with MD 10 DE at 1:10 carrier to extract ratio had lowest moisture content of 2.22 and 2.51% respectively. Based on the superior physico-chemical properties, freeze encapsulate of the freeze dried varikka and koozha extract prepared with 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3), using 20 DE maltodextrin at 1:20 carrier to extract ratio, was selected for part 4 of the experiment. 312 The encapsulated extracts were utilized @ 0.01 to 0.1 per cent for development of fortified mango RTS beverages as per FSSAI standards and compared with commercial fortified beverage in the fourth part of study. Mango RTS beverage enriched with the freeze encapsulate of the extracts @ 0.05 per cent was found to be superior with respect to Total Soluble Solids, total phenolic content, antioxidant activity and total sugar content and these were on par with the beverage enriched with spray encapsulates @ 0.05 per cent and commercial fortified beverages. The highest TPC of 41.05 and 41.12 mg GAE 100 ml-1 were recorded in mango RTS beverage enriched with 0.05 per cent freeze encapsulate of varikka and koozha respectively which were found to be on par with the mango RTS beverage enriched with 0.05 per cent spray encapsulate. The highest scavenging activity (76.29 per cent inhibition) was noticed in RTS beverage enriched with 0.05 per cent freeze encapsulate, followed by the beverage mixed with 0.05 per cent spray encapsulate (73.21%). The lowest scavenging activity (55.19 per cent inhibition) was observed in control sample. From the study, it was proved that the extracts prepared from combined inedible parts of both varikka and koozha jackfruit types are potential source for bioactive compounds. Extraction of freeze dried varikka and koozha types using 60 per cent ethanol at 1:50 solid to solvent ratio was standardized as the best extraction method for retention of phytochemicals, antioxidant activity, antihyperglycemic and anti-cancerous properties. Phytochemical profiling of the superior extracts revealed the presence of 15 sugars, 10 organic acids, 18 phenolic acids and 15 flavonoids. Extracts from varikka and koozha spray encapsulated using 20 DE maltodextrin at 1:20 carrier to extract ratio with 180 - 80°C inlet - outlet temperature and freeze encapsulated by using 20 DE maltodextrin at 1:20 carrier to extract ratio retained maximum phytochemicals and antioxidant properties. These spray and freeze encapsulates could be utilized for fortifying mango RTS beverage @ 50 mg 100 ml-1 without affecting the sensory parameters with an enhanced antioxidant activity of 13-16% compared to commercial fortified mango RTS beverage.ThesisItem Open Access Post harvest characterisation and management of avocado(Persea americana Mill.)(Department of Post Harvest Technology, College of Agriculture, Vellanikkara, 2022) Geethu, M; KAU; Saji GomezAvocado is a subtropical fruit crop, belonging to the family Lauraceae, and is rich in proteins, vitamins, minerals and monounsaturated fatty acids such as oleic acid, contributing to its high nutritive and therapeutic value. Even though there are a large number of genotypes with widely varying characteristics, inadequate characterisation and identification result in the lack of awareness, improper utilisation and insufficient post harvest management of avocado. Hence, the present study titled, „Post harvest characterisation and management of avocado (Persea americana Mill.)‟ was carried out in the Department of Post Harvest Technology, College of Agriculture, Vellanikkara during 2018-2021. The main objectives of the study were to characterise avocado accessions collected from different parts of Kerala and to evaluate the effect of post harvest management practices to extend the shelf life of avocado fruits and to study the effect of food additives on the quality of frozen slices, fruit pulp, freeze dried fruit powder and subsequently to standardise an instant avocado fruit shake. For the characterisation of avocado genotypes, 27 accessions were collected, among which 14 accessions were from RARS, Ambalavayal in Wayanad and 12 from Kanthaloor in Idukki and one accession was collected from Thanniyam in Thrissur. Characterisation of avocado genotypes based on the horticultural and biochemical traits, accession 25 from Idukki had comparatively higher TSS, vitamin C, total carbohydrates, total flavonoids, oleic acid, calcium, potassium, iron, total ash and crude fibre content. Hence, accession 25 was selected for subsequent post harvest management studies. Antioxidant activity of the methanolic extract of fresh fruit of accession 25 was evaluated by DPPH, FRAP and ABTS assays. Greatest free radical scavenging activity was observed in ABTS assay with lowest IC50 value of 0.10 μg/mL. Fresh and mature avocado fruits, surface sanitised with 2 ppm ozone and pretreated with 2 % calcium chloride, followed by shrink packaging with 25 μ polyolefin film and subsequently stored in refrigeration (T8) as well as cool chamber (T9) were found to be the ideal storage conditions with longest shelf life of 27 days. Calcium chloride pre-treated fruits with shrink packaging, stored under refrigeration had lowest physiological lossin weight, respiration rate, ethylene evolution rate and decay per cent, with better retention of firmness. Fruits of this treatment retained significantly higher total carbohydrates, total protein and total phenols during storage. Avocado slices pre-treated with 40 % sucrose, ascorbic acid (0.5 %) and potassium metabisulphite (0.1 %), quick frozen to -20 ºCin 30 minutes followed by packing in 200 gauge LDPE pouches and held under frozen temperature (-18 0C) was the most ideal pre-treatment for storage. This treatment recorded significantly higher TSS, vitamin C, total carbohydrates, total protein and organoleptic acceptability throughout storage and lowest water activity, peroxide value and microbial population. For preparation and storage of avocado pulp, pre-treatments with ascorbic acid (0.5%) and KMS (0.1%) followed by vacuum packaging LDPE bags (T10) as well as in glass jars (T12), stored under refrigeration resulted in longest shelf life and better quality. Total protein, total phenols, total carbohydrate, total fat, viscosity and organoleptic scores were highest in these treatments with lowest water activity, polyphenol oxidase activity and microbial population during storage. For preparation of avocado fruit powder, addition of 5% maltodextrin, ascorbic acid (1%), tricalcium phosphate (0.15%), EDTA (0.05%) and potassium sorbate (0.05%) followed by freeze drying at -70 ºCand 100 mtorr vacuum for 36 hours followed by packing in LDPE laminated aluminium pouches (T14) and glass jars (T16) stored under refrigeration were the ideal methods with longest shelf life and quality. Significantly higher bulk density, solubility, colour value L*, TSS, vitamin C, total carbohydrates, total fat and organoleptic scores were recorded in these treatments during storage along with lowest hygroscopicity, colour value a* and b*, peroxide value, water activity and microbial population. An instant avocado shake was standardised by combining avocado fruit powder with skimmed milk powder, sucrose and water in the proportion of 1:2:1:2 with appealing appearance, light yellowish colour, unique blend of taste and flavour of avocado fruit and skimmed milk powder.ThesisItem Embargo Jackfruit (Artocarpus heterophyllus Lam.) as a potential source of bioactive compounds(Department of Post Harvest Technology, College of Agriculture, Vellayani, 2022) Viresh; KAU; Mini, CAn investigation on “Jackfruit (Artocarpus heterophyllus Lam.) as a potential source of bioactive compounds” was carried out at Department of Post Harvest Technology, College of Agriculture, Vellayani from 2017-2020 with the objectives to standardize the extraction procedure for maximizing the antioxidant, anti-cancerous and anti-hyperglycemic properties of fruit wastes from varikka and koozha jackfruit types, phytochemical profiling, encapsulation and commercial exploitation of encapsulated extracts for fortification of fruit juice beverages. Experiments were carried out in four parts. Standardization of extraction procedure was carried out in the first part by evaluating the extracts for antioxidant, anti-hyperglycemic and anti-cancerous properties. Both varikka and koozha types were harvested at optimum maturity and were utilized at ripe stage independently. Except bulb, seed and peel without horny portion, all other parts were dried in cabinet (D1) and freeze (D2) driers, pulverized to fine powders and extracts were prepared using solvents viz., methanol at 90 (S1), 80 (S2), 50% (S3) and ethanol at 60 (S4), 80 % (S5) with solid to solvent ratios of 1:30 (R1), 1:40 (R2) and 1:50 (R3). Extract of freeze dried varikka samples using 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3) had highest Total flavonoid content (TFC) (15.66 mg QE 100g-1 ), Total phenolic content (TPC) (156.10 mg GAE 100g), DPPH scavenging activity (69.29 per cent inhibition) and α-glucosidase inhibition activity (90.24 per cent). The same extract, D2S4R3 from koozha also exhibited highest TFC (15.88 mg QE 100 g -1 ), TPC (164.63 mg GAE 100g), DPPH scavenging activity (68.64 per cent inhibition) and α-glucosidase inhibition activity (92.28 per cent). Freeze dried varikka samples extracted using 90 per cent methanol at 1:50 solid solvent ratio (D2S1R3) recorded the highest (45.88 mg 100g-1 ) ascorbic acid content and freeze dried koozha samples extracted using 90% methanol at 1:40 solid solvent ratio (D2S1R2) had the highest ascorbic acid content of 47.37 mg 100g-1 . 310 Based on the efficiency and economics, extraction of freeze dried samples using 60% ethanol at 1:40 solid to solvent ratio (D2S4R2), similar samples using 60% ethanol at 1:50 solid to solvent ratio (D2S4R3 ) and cabinet dried samples with 60% ethanol at 1:50 solid to solvent ratio (D1S4R3) were selected as three superior extraction methods . The MTT system which is a simple, reproducible and accurate means of measuring the activity of living cells via mitochondrial dehydrogenases was utilized to assess the anti-cancerous properties of the selected three extracts viz., D2S4R2, D2S4R3 and D1S4R3 on HeLa cell lines with doxorubicin as control. Freeze dried varikka and koozha samples extracted in 60 percent ethanol at 1:50 solid to solvent ratio (D2S4R3) had the lowest IC50 value of 129.30 and 157.60 µg mL-1 respectively whereas the IC50 value for doxorubicin (positive control) was18.85 µg mL-1 . When the three superior extracts were subjected to phytochemical profiling in the second part of the experiment using LCMS/MS (Waters UPLC H class system fitted with TQD MS/MS system) for sugars, organic acids, phenolic acids and flavonoids, they were significantly influenced by extraction methods and jack fruit types. Fifteen sugars, ten organic acids, eighteen phenolic acids and fifteen flavonoids were fractionated and identified from the extracts. Extract of freeze dried sample using 60% ethanol in 1:50 solid to solvent ratio (D2S4R3) had highest sugars, organic acids, phenolic acids and flavonoid content. The major sugars identified were fructose, glucose, mannose, sucrose and sorbitol and; organic acids were citric acid, malic acid, shikimic acid, succinic and hydroxycitric acid; phenolic acids were ferulic acid, p-coumaric acid, caffeic acid, benzoic acid, o - coumaric acid; myricetin, catechin, naringenin, quercetin and epicatechin were the major flavonoids. The three superior extracts selected were encapsulated independently by spray and freeze drying in the third part of the study. Two maltodextrin (MD) levels (10 and 20 dextrose equivalence, DE), three carrier to extract ratio (1:10, 1:15 and 1:20), two inlet- outlet temperature of spray drier (180 - 80º C inlet - 311 outlet and 190 - 90º C inlet - outlet) were the process variables for spray encapsulation, whereas for freeze encapsulation, maltodextrin (MD) levels and carrier ratio were selected as process variables. The extract D2S4R3 from varikka and koozha, spray encapsulated using MD 20 DE at 1:20 carrier to extract ratio (Cr3) at inlet and outlet temperature of 180 and 80º C (T1) recorded highest TPC of 115.47 and 117.92 mg GAE 100 g-1 respectively. Varikka and koozha extracts spray encapsulated using MD 20 DE at 1:10 carrier to extract ratio at 190 - 90ºC inlet - outlet temperature (C2Cr1T2) produced encapsulate with highest per cent recovery (83.77 and 82.09 % respectively). Lowest moisture content of 2.46 and 2.55 per cent were recorded by the extracts spray encapsulated using 10 DE MD at 1:20 carrier to extract ratio at inlet - outlet temperature of 190 - 90º C (C1Cr3T2) from varikka and koozha respectively. Based on the superior physico-chemical properties, spray encapsulate of freeze dried varikka and koozha extracts prepared using 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3), using 20 DE maltodextrin at 1:20 carrier to extract ratio with 180 - 80°C inlet - outlet temperature (C2T1Cr3), was selected for Part 4 of the experiment. D2S4R3 extract from varikka and koozha, when freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio had highest TFC of 11.62 and 11.75 mg QE 100 g-1 respectively. Koozha extract, freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio had highest TPC of 134.38 mg GAE 100 g-1 DPPH scavenging activity of varikka and koozha extracts were highest when freeze encapsulated with MD 20 DE at 1:20 carrier to extract ratio (per cent inhibition of 71.66 and 77.48 respectively). Ascorbic acid content and per cent recovery of encapsulates were not influenced by levels of MD or carrier to extract ratio. The extracts freeze encapsulated with MD 10 DE at 1:10 carrier to extract ratio had lowest moisture content of 2.22 and 2.51% respectively. Based on the superior physico-chemical properties, freeze encapsulate of the freeze dried varikka and koozha extract prepared with 60 per cent ethanol at 1:50 solid to solvent ratio (D2S4R3), using 20 DE maltodextrin at 1:20 carrier to extract ratio, was selected for part 4 of the experiment. 312 The encapsulated extracts were utilized @ 0.01 to 0.1 per cent for development of fortified mango RTS beverages as per FSSAI standards and compared with commercial fortified beverage in the fourth part of study. Mango RTS beverage enriched with the freeze encapsulate of the extracts @ 0.05 per cent was found to be superior with respect to Total Soluble Solids, total phenolic content, antioxidant activity and total sugar content and these were on par with the beverage enriched with spray encapsulates @ 0.05 per cent and commercial fortified beverages. The highest TPC of 41.05 and 41.12 mg GAE 100 ml-1 were recorded in mango RTS beverage enriched with 0.05 per cent freeze encapsulate of varikka and koozha respectively which were found to be on par with the mango RTS beverage enriched with 0.05 per cent spray encapsulate. The highest scavenging activity (76.29 per cent inhibition) was noticed in RTS beverage enriched with 0.05 per cent freeze encapsulate, followed by the beverage mixed with 0.05 per cent spray encapsulate (73.21%). The lowest scavenging activity (55.19 per cent inhibition) was observed in control sample. From the study, it was proved that the extracts prepared from combined inedible parts of both varikka and koozha jackfruit types are potential source for bioactive compounds. Extraction of freeze dried varikka and koozha types using 60 per cent ethanol at 1:50 solid to solvent ratio was standardized as the best extraction method for retention of phytochemicals, antioxidant activity, antihyperglycemic and anti-cancerous properties. Phytochemical profiling of the superior extracts revealed the presence of 15 sugars, 10 organic acids, 18 phenolic acids and 15 flavonoids. Extracts from varikka and koozha spray encapsulated using 20 DE maltodextrin at 1:20 carrier to extract ratio with 180 - 80°C inlet - outlet temperature and freeze encapsulated by using 20 DE maltodextrin at 1:20 carrier to extract ratio retained maximum phytochemicals and antioxidant properties. These spray and freeze encapsulates could be utilized for fortifying mango RTS beverage @ 50 mg 100 ml-1 without affecting the sensory parameters with an enhanced antioxidant activity of 13-16% compared to commercial fortified mango RTS beverage.ThesisItem Open Access Evaluation and utilisation of edible lichen parmotrema tinctorum (Nyl.) hale for food preservation(Department of Post Harvest Technology, College of Horticulture, Vellanikkara, 2018) Anupama, T V; KAU; Sheela, K BInvestigation on “Evaluation and utilisation of edible lichen Parmotrema tinctorum (Nyl.) Hale for food preservation” was carried out in the Department of Post Harvest Technology, College of Horticulture ,Vellanikkara during 2014-2017. The main objectives of the study were to evaluate the biochemical constituents, proximate composition, antimicrobial activity, feasibility for food preservation and to study the toxicological effect of the lichen Parmotrema tinctorum. The lichen samples were collected from Chembra, Meppadi, Moolankavu and Ambalavayal areas in Wayanad district, and they were identified as Parmotrema tinctorum by colour spot tests. The samples read K-, C+, KC+ and Pd- for the lichen Parmotrema tinctorum. The habitat of lichen was found to be the shady places of the evergreen forests at 736m -2100m above MSL. Parmotrema tinctorum is found to be corticolous (growing on the surface of trees) in habit. Thallus of the lichen is foliose, loosely attached, lobes irregular, margins entire, upper surface grey, smooth, shining; lower surface black and marginal area brown. Proximate analysis of Parmotrema tinctorum revealed a high content of total protein (15.70 %), crude fibre (14.16%), ash (10.50%) and total phenols (322 mg/100g). Parmotrema tinctorum also contained total carbohydrate (20.03 g/100g), crude fat (1.28%), ascorbic acid (4.66 mg/100g) and total free amino acids (8.25 mg/g). High content of calcium, magnesium, potassium and iron were found in the mineral analysis of Parmotrema tinctorum. Methanol, ethyl acetate and acetone extracts of Parmotrema tinctorum were analysed for antioxidant activity by DPPH and ABTS assays, and the highest scavenging action was detected in the methanol extract against the DPPH free radicals (IC50-1.47 mg/ml) and the ABTS radicals (IC50-1.27 mg/ml). Preliminary phytochemical screening of Parmotrema tinctorum revealed maximum phytochemicals in methanol extract viz. carbohydrates, phenols, flavonoids, tannins, terpenoids, fixed oils and coumarins. The TLC profiling of lichen extracts (hexane, methanol and acetone) showed maximum compounds in acetone extract, and the spots indicated the presence of phenols and terpenoids. A range of volatile compounds were observed when the lichen extracts (methanol, hexane, acetone, chloroform and ethanol) were subjected to GC-MS analysis.Volatile compounds with antimicrobial properties identified were orcinol, methyl orsellinate, atraric acid, atranorin, methyl haematommate, glyceryl trilaurate, lauric acid vinyl ester and gamma-sitosterol. In vitro testing of antimicrobial activity of acetone, ethanol and chloroform extracts of Parmotrema tinctorum using disc and well diffusion methods revealed their inhibitory action against the selected food spoilage organisms. Ethanol extract (EE) of Parmotrema tinctorum produced maximum inhibition of Aspergillus niger, while chloroform extract (CE) produced maximum inhibition of Aspergillus oryzae. The growth of both yeast species, Saccharomyces cerevisiae and Zygosaccharomyces bailii, was found to be inhibited maximum by the ethanol extract followed by the chloroform extract of the lichen Parmotrema tinctorum. In both disc diffusion and well diffusion methods, the growth of Bacillus subtilis and Staphylococcus aureus were remarkably inhibited by the acetone extract (AE) followed by chloroform extract (CE) forming zones of inhibition at all the concentrations tested. Feasibility of utilizing Parmotrema tinctorum for food preservation was evaluated by adding in powder and in ethanol extract form in two processed products viz. lime pickle and tomato sauce. In lime pickle, bacterial count was least in treatments T8 and T7 (added with 0.3% and 0.2% ethanol extracts respectively). Product preserved with 250 ppm sodium benzoate (T2) revealed least fungal count (0.6x103 CFU/g), which was on par with that containing 0.3% ethanol extract (1.0x103 CFU/g). Lowest yeast count was observed in T8, followed by T2 (0.3 x103 CFU/g). The shelf life of lime pickle treated with T2 (product preserved with 250 ppm sodium benzoate) was estimated to be six months, while that of T8 (product treated with 0.3% ethanol extract) was found to be five months. Unpasteurised tomato sauce in which 0.1% ethanol extract was added had significantly lower bacterial count (5.2X106 CFU/g). The tomato sauce preserved with 750 ppm sodium benzoate recorded lowest fungal and yeast count. The products added with 0.05% and 0.1% ethanol extract of lichen also recorded lower fungal and yeast counts. Microbial analysis of products showed the relevance of ethanol extract as an alternative to sodium benzoate in preventing the microbial spoilage of foods. Sensory analysis revealed that lichen extract added products were acceptable for consumption. Acute oral toxicity study of the ethanol extract of Parmotrema tinctorum conducted in Wistar rats revealed the absence of clinical signs of toxicity and mortalities. There were no treatment related changes in body weight and gross pathological changes in the test animals. Single dosing of ethanol extract of Parmotrema tinctorum upto a dose of 2000 mg/kg body weight orally was found to be safe in Wistar rats.ThesisItem Open Access Aloe vera based edible film coating for shelf life extension in tomato (solanum iycopersicum)(Department of Post Harvest Technology, College of Agriculture, Vellayani, 2018) Thushara, T Chandran; KAU; Mini, CThe present investigation on “Aloe vera based edible film coating for shelf life extension in tomato (Solanum lycopersicum)” was carried out at the Department of Post Harvest Technology, College of Agriculture, Vellayani during the period of 2014-2017, with the objective to standardise an Aloe vera gel based edible film coating for tomato fruits to withstand storage and transportation losses and thereby formulate a viable and efficient post harvest management practice for extending shelf life of tomato. A preliminary trial was conducted for standardization of Aloe vera gel based edible film using four different gelling agents (INS 401, 402, 440 and 508), seven concentrations (1, 2, 5, 10, 15, 25 and 35%) and five durations (1, 2, 5,10 and 15 minutes) for extending shelf life of tomatoes. Based on the physiological loss in weight and shelf life obtained, 12 superior treatment combinations including INS 401 and 402 at 1 and 2% concentrations dipped for 1, 2 and 5 minutes were selected for further study of the experiment. Further experiments were carried out as four different steps using tomato variety Akshaya, harvested independently at two different maturity stages viz., mature green and firm ripe which were meant for distant and local market transportation respectively. Evaluation of the selected 12 aloe gel based edible films on quality parameters revealed the superiority of aloe gel based treatments over untreated fruits harvested in both the maturity stages. Shelf life of aloe gel based edible film coated mature green and firm ripe tomatoes were 36 and 24 days respectively. On the 36th day of storage all the aloe gel based treatments were equally effective in maintaining chemical and microbial quality parameters of the mature green tomato fruits, but fruits dipped in 2% aloe gel + INS 402 for two minutes recorded least PLW and percent leakage and hence had higher scores for sensory parameters. Firm ripe fruits dipped in aloe gel +INS 402 (1%) for one minute had superior physical and physiological parameters on 24th day of storage. The possibility of increasing the efficiency of aloe gel based formulation by incorporation of natural and cheap plant leaf extracts from papaya, guava and ocimum in 1:1 and 1:2 ratios for shelf life extension in tomato was assessed. Considering the economics and efficiency in maintaining better physiological quality parameters, 2% papaya leaf incorporated aloe gel (1:2) + INS 402 for two minutes was selected as the best plant leaf extract incorporated aloe gel (PLEAG) treatment for mature green fruits and 1% papaya leaf incorporated aloe gel (1:2) + INS 402 for one minute for firm ripe tomatoes. Quality evaluation of edible coatings revealed better efficiency of papaya leaf incorporated aloe gel (1:2) in reducing the activity of texture affecting enzymes viz., pectin methyl esterase and polygalactouronase and increasing total pectin content resulting in higher fruit firmness in both mature green and firm ripe tomatoes. Even though no antimicrobial activity against Erwinia and Rhizopus was noticed when tested under in vitro condition, the aloe based extracts had suppressed the post harvest infection by these pathogens in vivo. Efficiency of the selected papaya leaf incorporated aloe gel (1:2) in reducing post harvest loss during storage and transportation was compared with that of a commercial wax formulation independently for mature green and firm ripe tomato fruits after packaging in 5% ventilated corrugated fiber board (CFB) boxes with and without moulded tray. When packaged fruits were stored under optimum low temperature (12- 200C for mature green and 10-150C for firm ripe) and ambient temperature (28-300), low temperature storage was superior in maintaining the quality parameters for both the maturity stages of tomato. Packaging in 5% ventilated CFB boxes with moulded tray was effective in maintaining the physical and physiological parameters of mature green tomato during storage. Papaya leaf incorporated aloe gel (1:2) was equally effective as the commercial bee wax formulation in maintaining the physiological, chemical, and microbial parameters. Fruits coated with commercial bee wax had reduced lycopene content and a non- uniform fruit colour development and hence recorded poor sensory scores. Though both the packaging systems were equally effective in maintaining all the quality parameters during storage of firm ripe tomatoes, overall acceptability was higher for fruits kept in 5 % ventilated CFB box with molded trays. Papaya leaf incorporated aloe gel (1:2) was equally effective as the commercial wax formulation for the stored firm ripe tomatoes too. Studies to analyze the efficiency of aloe gel based coatings to withstand transportation losses revealed the superiority of 5% ventilated CFB box with moulded tray and effectiveness of papaya leaf extract incorporated aloe gel (1:2) in maintaining all the quality parameters in fruits of both maturity stages. Cost of production for coating the standardized papaya leaf incorporated aloe gel was Rs. 45.87/- for 100 Kg mature green tomatoes and Rs.23.65/- for 100 Kg firm ripe tomatoes. Based on the study, an efficient postharvest management practice for shelf life extension in tomato fruits of both maturity stages could be formulated. Mature green tomato fruits cv. Akshaya after washing and surface sanitization using 2ppm ozonized water for five minutes followed by coating with papaya leaf incorporated aloe gel (1:2) + INS 402, (2%) for two minutes, air drying and packaging in 5% ventilated CFB boxes with moulded tray had a storage life of 60 days under optimum low temperature (12-200C) or could be transported to distant markets without transportation hazards. Firm ripe tomato fruits cv. Akshaya could be stored for 36 days using the same protocol except coating with papaya leaf incorporated aloe gel (1:2) + INS 402, (1%) for one minute and storing at an optimum low temperature of 10-150C or could be transported to local markets without any hazards.
