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Subject: Microbiology × Author: Navjot Kaur × Start date: 2000 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Production of probiotic Aloe vera juice
    (Punjab Agricultural University, Ludhiana, 2021) Navjot Kaur; Katyal, Priya
    Aloe Vera juice is rich in vitamins, minerals, fibers, nutrients, anthraquinones, saponins, phytosterols and salicylic acid. Its composition proves it to be an excellent source of prebiotics and a potential substrate for probiotics. Though Aloe Vera juice has been used for its medicinal and health benefits since ages, its value addition by converting it into a synbiotic is lesser exploited so far. This investigation involves physicochemical, microbiological, antioxidant and sensory evaluation of probiotic Aloe vera juice developed at the lab scale by using Lactobacillus acidophilus MTCC 10307. The probiotic culture was inoculated to the Aloe vera juice with initial concentration of 109-1010 CFU/ml. The probiotic viability, pH, total soluble solids (TSS), titrable acidity, total sugars, reducing sugars, non-reducing sugars, lactic acid content, anti-oxidant activity, vitamin C and microbial contaminations were measured at weekly interval upto six weeks. The probiotic viability remained above 8 log CFU/ml during the first four weeks of storage at 4°C. The total plate count, coliform count and yeast and mould count also remained within satisfactory limits. The developed probiotic aloe vera juice was exposed to sensory analysis by a panel of five semi trained judges on the basis of nine-point hedonic scale. Statistical analysis showed a significant difference in taste, texture, aroma, mouth feel of the aloe vera juice and probiotic aloe vera juice, with nonsignificant difference in appearance, color and overall acceptability at 5% level of significance. Though taste of probiotic aloe vera juice scored less but difference in overall acceptability was non-significant. The sensory evaluation of aloe vera juice with and without probiotic inoculation revealed it to be potential synbiotic product.
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    ThesisItemOpen Access
    CHARACTERIZATION OF NARINGINASE ENZYME FOR PRODUCTION OF DEBITTERED LOW ALCOHOLIC NATURALLY CARBONATED KINNOW BEVERAGE
    (PAU Ludhiana, 2013) Navjot Kaur; Param Pal, Sahota
    Naringin, the bitter flavonone glycoside and primary bitter component in citrus fruit juices can be hydrolysed by naringinase enzyme into tasteless component, naringenin. A rapid detection test for naringinase producing microorganisms using FeCl3 has been developed. Naringin an inducer in kinnow juice, mutated yeast Clavispora lusitaniae and induced the production of crude enzyme naringinase with the activity of 0.0135 IU/ml. The parameters optimized for naringinase production were pH (4), temperature (50°C), naringin (0.8%) and rhamnose concentration (0.6%) with high substrate activity Km value of 1.00 mM and Vmax value of 28.56 mM. Divalent cations Cu2+ and Ca2+ competitively inhibited enzyme activity where as Mn2+ and Zn2+ stimulated enzyme activity of 0.024 IU/ml and 0.0079 IU/ml, respectively. The debittering of kinnow juice by Clavispora lusitaniae mutant prompted for utilization of kinnow juice for the production of low alcoholic naturally carbonated fermented kinnow beverage. Technology for the production of low alcoholic naturally carbonated fermented kinnow beverage with yeast Clavispora lusitaniae under optimized fermentation conditions were developed. Microbiological, physiochemical and sensory evaluation of kinnow beverage with 40 percent juice revealed pH 4.2, TSS 10.5°B, acidity 0.53%, ascorbic acid 9.2 mg/100ml, reducing sugar 8.83 percent, total sugars 9.4 percent, limonin 1.7 ppm, naringin 120.8 ppm, β-carotene 0.26μg/L, alcohol 0.28% (w/v), CO2 1.09 bar and plate count 9.3x108 cfu/ml, ranked highest for taste 7.9, aroma 8.5, colour 7.8, astringency 8.25 and overall acceptability 7.8 during storage period of 70 days under refrigerated conditions (4°C). The percentage decrease in limonin and naringin on storage was 54 and 64.8 percent, below the threshold level of limonin (6 ppm) and naringin (600 ppm) respectively. The pasteurization conditions standardized for kinnow beverage were 85°C for 3 sec.