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20185
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Subject: Food Technology × End date: 2018 × Start date: 2018 × Type: Thesis ×
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    ThesisItemOpen Access
    READY-TO-RECONSTITUTE MIX FROM MAKHANA (Euryale ferox) SEEDS
    (AAU, Jorhat, 2018) Kalita, Upama; Das, Manashi Purkayastha
    Makhana, an underutilize aquatic crop of Nympheaceae family, has various medicinal properties but has not gain much attention in the field of processed products and marketing. Value added product from makhana can be envisaged; however development of suitable processing technique for the same is still lacking. The objective of the study is to develop nutritious ready –to-reconstitute mix formulation using makhana as the prime ingredient. Makhana seed was ground into flour which was found to contain high amount of carbohydrate (69.06%) and protein (~9.69%). Makhana flour was subjected to two processing techniques i.e. roasting (100o C for 1, 3 and 5min) and steaming (100o C for 10, 15, 30, 45 and 60 min) for improving resistant starch (RS) content. RS was found to be highest in S8 (steaming for 60 min), followed by S2 (roasting for 3min) and S3 (roasting for 5min). Though steaming improved the RS content in makhana flour upto 0.92%, however the off-odour of steamed samples made them organoleptically unacceptable. While roasting eliminated the off-odour of makhana and also improved the RS value (0.58% to 0.84%); wherein S2 (0.84%) had the highest overall acceptability. As such S2 was selected for formulating ready-to-reconstitute mix by adding it with fig and banana flour at different proportion .These formulations were reconstituted in water /milk for assessing rehydration ratio, viscosity and sensory analysis. Rehydration ratio and viscosity were found maximum in T9 (60% makhana, 30% fig,10% banana) followed by T8 (60% makhana, 10% fig, 30% banana).High viscosity and rehydration ratio in these formulations were attributed to the presence of high amount of fig and banana flours having high crude fiber (2.08 % in banana and 4.14 % in fig).All the formulations received high mean score for colour, appearance and texture, taste, flavor and overall acceptability except T1 (contain makhana flour as control). The comments from the panelist revealed that natural sweetness of fig and banana sufficed the need of any extraneous sweetener in the formulations excluding the control (T1), where makhana gave a bland taste. T8 (60% makhana, 10% fig, 30% banana) scored the highest overall acceptability and was thus found to be suitable for making ready-to-reconstitute mix. Hence, suitably makhana flour (roasting) can be blended with other fruits and vegetables for making convenient foods.
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    ThesisItemOpen Access
    BAKERY PRODUCTS FROM COMPOSITE FLOUR USING FRUIT PULP CONCENTRATE
    (AAU, Jorhat, 2018) Koch, Parismita; Barooah, Mridula Saikia
    The consumer demand is increasing for bakery products having high nutritional value and potential health benefit. The primary objective of the study is to produce baked goods using partial substitution of fat with papaya pulp concentrate and wheat flour with buckwheat and defatted soya flour. Cookies and muffins were prepared with different composite flour treatments of refined wheat flour, buckwheat flour and defatted soy flour in the ratio of 80:10:10 (T1). 70:20:10 (T2) and 60:30:10 (T3). Papaya pulp concentrate was obtained after drying papaya pulp at 60°±2°C for a period of 60, 90 and 120 minutes. The pulp concentrate with 120 minutes of drying was selected which contained total soluble solid content (20.5 ⁰Brix) double than that of the fresh pulp. This papaya pulp concentrate was used at 20%, 30%, 40% and 50% levels for replacing fat during baking. The organoleptic evaluation using 9 point hedonic scale revealed that cookies from the three composite flour treatments with 30% level of fat replacement scored highest in all the sensory attributes while for muffins, the composite flour treatments with 40% level of fat replacement received the highest scores. The physico-chemical analysis indicated that cookies and muffins of composite flour treatment T1 had the lowest fat content whereas composite flour treatment T3 for both the products were higher in nutritional composition. The protein, fiber and ash content of cookies increased to 17.82 g/100g, 2.27 g/100g and 1.56 g/100g with DPPH inhibition % 60.13% respectively and fat content decreased to 19.37 g/100g in comparision to control with 23.82 g/100g. For muffins, the protein, fiber and ash content increased to 19.02 g/100g, 2.35 g/100g and 1.79 g/100g with DPPH inhibition % 61.07% respectively and fat content decreased to 13.84 g/100g in comparision to control with 18.77 g/100g. The shelf-life of papaya pulp concentrate with different treatments was upto 5 days after which visible growth appeared. The pulp concentrate with preservative stored in refrigerator had the least microbial count on fifth day. The shelf-life of cookies packaged in air tight container and HDPE packages were upto 90 days in regard to both microbial load and sensory evaluation. The muffins were acceptable up to 14 days after which visible growth was visible. The overall acceptability of the bakery products decreased with increase in storage period. Thus it can be concluded that use of composite flour and papaya pulp concentrate in baked foods causes increased overall nutritional quality, decreased fat content and thereby trans fat and calorie content.
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    ThesisItemOpen Access
    YOGHURT DEVELOPMENT FROM NON-DAIRY PLANT SOURCES
    (AAU, Jorhat, 2018) Deka, Pampi; Saikia, Ananta
    Investigations were carried out at the Departments of Horticulture and the Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat, during 2016-2018 on yoghurt developement from non-dairy plant sources like taro and tapioca. The yoghurts were prepared by infusing taro and tapioca in soymilk using bacterial cultures collected from the Depatment of Agricultural Biotechnology and isolates from commercial yoghurts. Isolated strains were identified as Streptococcus thermophilus PD5 MH569615, L. delbrueckii subsp. lactis PD7 MH569616 and L. brevis PD8 MH569617 for milk fermentation with the help of 16S rDNA gene sequencing. Those strains were phylogenetically similar with their related species. Through sensory evaluation of yoghurt samples, four yoghurts were selected as best and those samples were AB9 (1:9 taro-soy yoghurt; 1:1 S. thermophilus and L. delbrueckii subsp. lactis), CD19 (1:9 tapioca-soy yoghurt; 1:1 S. thermophilus and L. delbrueckii subsp. lactis), CDY (1:9 tapioca-soy yoghurt; 1:1 S. thermophilus and L. brevis), and CDZ (1.5:8.5 tapioca-soy yoghurt; 1:1 S. thermophilus and L. brevis). The selected yoghurt samples were subject to physio-biochemical and microbiological analysis which revealed that yoghurt AB9 contained the highest protein (6.47 g 100 g-1), fibre (0.25 g 100 g-1), viscosity (684.03 cP); but with the lowest moisture (81.73%), carbohydrate (3.66 g 100 g-1), fat (0.28 g 100 g-1), acidity (0.34%) and pH (4.20). On the basis of sensory evaluation and physio-biochemical properties, AB9 (1:9 taro-soy yoghurt; 1:1 S. thermophilus and L. delbrueckii subsp. lactis) was considered as the best. The microbiological examination revealed that yoghurt had a shelf life of 6 days with Lactobacilli count of 6.63 log cfu mL-1, S. thermophilus count of 6.84 log cfu mL-1 with absence of coliform bacteria.
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    ThesisItemOpen Access
    Evaluation of Acetic Acid Bacteria for Production of Organic Vinegar from Chepa guti, a waste by product of rice based alcoholic fermentation
    (2018) Neog, Noopur Ranjan; Barooah, M.
    Chepa guti, a byproduct of the Xaj-brewing process is the lees left behind after the liquid is separated from the fermented product. The technological advance in the field of rice brewing is expected to witness an upsurge in brewing plant and an increase generation of this byproduct. Chepa guti is specifically seen to retain starch and fermentable sugars which can be used to produce down stream products like acetic acid. Chepa guti collected from different localities were used as a source for isolation of acetic acid bacteria. Three isolates that matched acetobacter species on biochemical level were further characterized at the molecular level through 16SrDNA gene sequencing and identified as Acetobacter indonesiensis, Acetobacter spp. and Acetobacter tropicalis. The collected chepa guti was initially characterized at the biochemical level and subjected to hydrolysis with commercial alpha-amylase at different concentration for generating maximum amount of reducing sugar. The aamylase at 0.3 per cent concentration in 1:1.5 substrate dilution (substrate : water) along with fungal culture Amylomyces rouxii ABT82 (NCBI KP790015) at 48 hours of incubation time produced maximum reducing sugars (73.41 mg 100mL-1). Simultaneous saccharification and fermentation using the yeast isolate Saccharomyces cerevisiae ADJ 5 (NCBI KX904349) produced 8.19 % ethanol. This substrate was used to produce acetic acid by inoculating pure culture of isolated acetic acid bacteria viz., Acetobacter indonesiensis , Acetobacter spp , Acetobacter tropicalis along with a control inoculated with reference strain Acetobacter aceti ATCC 15973 and treatment combination. Acetic produced by the pure culture of Acetobacter tropicalis was significantly higher in terms of acetic acid content of (9.08 %). It had pH (2.68), residual alcohol of (0.52 %), TSS of (0.91 ˚Brix), residual reducing sugar of (0.25 mg 100 mL-1) and protein content of (68.09 μg 100 mL-1). The LC-MS analysis of the produced acetic acid showed the presence of compounds like O-Phosphoserine, 2',3'-Dideoxyadenosine, Phenylalanine, 2-(4-Hydroxyphenyl) propionic acid, Creatine, N-Tigloylglycine, S-Sulforaphene, Triethyl phosphate, Metazachlor-OXA, Histidinol, Indole, Indoline, L-verbenone, Indole-3-carbinol, DL-Pipercolic acid, 1-Aminocyclopropane carboxylic acid. The Acetobacter tropicalis isolate was used in the scale up process where acetic acid content of (11.26 %) was achieved by increasing the inoculum size. The study reveals the potential of native acetic acid bacteria and development of a technology to produce organic acetic acid from bio-waste. The study was successful in isolating and identifying native acetic acid bacteria in Chepa guti and also was able to standardize the production of vinegar from the biowaste.
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    ThesisItemOpen Access
    UTILIZATION OF FRUITS AND VEGETABLE WASTE IN CEREAL BASED FOOD
    (AAU, Jorhat, 2018) Alkozai, Abdullah; Alam, Sheriful
    An experiment entitled “Utilization of fruits and vegetables waste in cereal based food” was conducted in the Department of Horticulture during 2016 -2018. Powder from the mango kernel, pineapple pomace, carrot pomace, banana peel and orange peel was prepared. The wheat flour in the cookies and cakes formulation was substituted by MKP (mango kernel powder), PPP (pineapple pomace powder), CPP (carrot pomace powder), BPP (banana peel powder) and OPP (orange peel powder) at the rate of 0, 10, 20 and 30 per cent. Cookies and cakes were prepared and were analyzed for its physical (diameter, thickness and spread ratio), functional (water holding capacity, oil holding capacity and swelling capacity), chemical (moisture, ash, protein, fat, fibre, carbohydrate) and sensorial characteristics (appearance, colour, Flavour, taste, texture, overall acceptability). On the basis of overall sensory attributes, cookies prepared with incorporation of 10 per cent of MKP, PPP, CPP, BPP and OPP recorded higher acceptability scores as compared to other samples. In case of cakes the basis of overall sensory attributes, cakes prepared with 10 per cent of, PPP, CPP, BPP, OPP and 20 per cent MKP recorded higher acceptability values as compared to other samples. The water absorption capacity differed significantly. The highest value of (2.66 ml/g) was recorded in CPX (wheat flour substituted with 10% carrot pomace powder), the lowest value of 1.10 ml/g was recorded in wheat flour cookies. The spread ratio of cookies increased with incorporation fruits and vegetable waste powder. However, the differences in spread ratio of cookies were non-significant. The peroxide values and moisture content of cookies and cakes increased with increasing storage time. Cookies containing 10 per cent mango kernel powder and cakes containing 20 per cent mango kernel powder scored higher values in sensory evaluation.