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Subject: Food Science and Technology × Author: Joshua, Rehema × Start date: 2018 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Biopreservation of pineapple wine using immobilized L. plantarum
    (CCSHAU, Hisar, 2020-08) Joshua, Rehema; Anju Kumari
    The present investigation entitled "Biopreservation of pineapple wine using immobilized L. plantarum" was conducted with the aim of immobilizing bacteriocin producing L. plantarum and preparing pineapple wine to study the effect of immobilized bacteriocin producing L. plantarum on shelf-life of pineapple wine. The immobilization was done using sodium alginate and CaCl2. L. plantarum had 91.87±1.74% viability after immobilization and 88.66±1.44% survival after freeze-drying of immobilized cells. The survival of immobilized cells was better than free cells in the simulated gastric-intestinal juices. Bacteriocin production was high in free cells at 72hours and decreased at 120 hours; while in immobilized cells it was high at 96hours and remained constant until 120 hours. The antimicrobial activity of bacteriocin from free cells and immobilized cells was checked against wine spoiling microorganisms and pathogenic bacteria (E. coli, S. aureus and B. subtilis).For shelf-life study, pineapple wine was treated with free cells, immobilized cells, potassium metabisulphite, nisin and freeze-dried microcapsules each at concentration of 100 μg/ ml at pH of 3.5 as the lethality rate was above 60% in all concentration set. Wine samples were chemically, microbial and organoleptically analyzed at monthly interval for three months of storage. No significant change in alcohol, total soluble solids, reducing sugar, titratable acidity, and pH was observed during storage. But significant decrease of reducing sugars and total sugars were observed in wine treated with free cells and immobilized cells. Total phenols and total sugar decreased with increase in storage time. No coliforms were detected during three months of storage. Wine treated with nisin and immobilized cells had high overall acceptability. The findings of this study revealed protective effect of calcium-alginate to the survival of bacteriocin producing L. plantarum in alcoholic and acidic conditions of pineapple wine during three months of storage. Immobilized bacteriocin producing L. plantarum therefore, could be used for biopreservation of wine.