Thumbnail Image

Kerala Veterinary and Animal Sciences University, Wayanad

Browse

2016 - 20172
Reset filters
Subject: Dairy Technology × End date: 2019 × Start date: 2010 × Type: Thesis × Thesis Type: M.V.Sc. ×
Reset filters

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ThesisItemOpen Access
    ISOLATION AND CHARACTERIZATIONOF ANGIOTENSIN CONVERTING ENZYME INHIBITORY PEPTIDES FROM FERMENTED GOAT MILK
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES-MANNUTHY,THRISSUR, 2017) SATHYA, P.; Radha, K.
    A study was conducted to isolate and characterize the angiotensin converting enzyme (ACE) inhibitory peptides from fermented goat milk and to compare the potential of selected lactic acid bacterial cultures for the release of angiotensin converting enzyme inhibitory peptides. Goat milk was fermented by using 14 different lactic acid bacterial cultures at three and four per cent inoculum levels. Fermented goat milk samples were analysed for pH, titratable acidity, lactic acid bacterial count, proteolytic activity and ACE inhibitory activity. The results showed that pH, titratable acidity, lactic acid bacterial count, proteolytic activity and ACE inhibitory activity varied significantly (p≤0.01) among milk samples fermented with different lactic acid bacterial cultures. The highest ACE inhibitory activity was observed in milk fermented with L. plantarum 379 (97.558 ± 0.965)at four per cent inoculum level. The lowest ACE inhibitory activity was observed in milk fermented with L. helveticus288(65.121± 0.963) at three per cent inoculum level. The corresponding IC50 values were 0.018 and 0.082 mg/ml. A positive correlation between proteolytic activity and ACE inhibitory activity was observed in milk samples fermented with L. helveticus 192, L. bulgaricus 009, L. plantarum 379 and L. casei 017. There was also a positive correlation between inoculum level and ACE inhibitory activity in milk samples fermented with L. helveticus 192, L. rhamnosus 024 and L.acidophilus (015 & 298).Among the 14 fermented milk samples, six samples (L. plantarum379 and 417, L. rhamnosus8712, L. acidophilus 10307, L.helveticus288 and L. bulgaricus009) with high ACE inhibitory activity were selected and peptides were separated by gel filtration column chromatography. Isolation of ACE inhibitory peptide was done by reverse phase high performance liquid chromatography. Characterization of ACE inhibitory peptide was done by Tristricine SDS PAGE which showed that the molecular weight of the identified peptide was 1.4 kDa.
  • Thumbnail Image
    ThesisItemOpen Access
    IMPACT OF SOMATIC CELL COUNT ON PHYSICOCHEMICAL QUALITY OF MILK AND FERMENTED MILK PRODUCTS
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES-MANNUTHY,THRISSUR, 2016) ANU JOSEPH, PEREKATTU; T.SATHIAN, C.
    Objectives of the research work were to find out the impact of somatic cell count (SCC) on the physicochemical properties of milk and on the quality of fermented dairy products, curd and yoghurt. The correlation between the somatic cell count and total DNA content isolated from the milk was also explored. In this study one hundred pooled cow milk samples were collected from farms and milk co-operative societies in Thrissur district. The samples were categorised into three groups based on SCC into low, intermediate and high. All the pooled cow milk samples were subjected to Methylene Blue Reduction Test, isolation and quantification of DNA. Somatic cell count, pH, titratable acidity, chloride content, and electrical conductivity of the samples were estimated. On analysis, it was found that pH showed a negative correlation and titratable acidity showed a positive correlation with high SCC category milk. Chloride content as well as electrical conductivity of milk showed a significant positive correlation (P< 0.01) with SCC in milk. An elevated somatic cell count in milk was associated with poor microbial quality of raw milk revealed by Methylene Blue Reduction Test. Pearson’s analysis showed a significant positive correlation (P<0.01) between the DNA yields extracted from the pooled cow milk and the milk Somatic cell count. Yoghurt and curd prepared from milk with varying SCC (low, intermediate and high) were evaluated for the starter activity, free fatty acid content, viscosity and sensory evaluation. The free fatty acid content of the high SCC yoghurt and curd were significantly higher than the low SCC yoghurt and curd (P<0.05). Starter activity of high SCC yoghurt was significantly lower (P<0.05) than the low and intermediate SCC yoghurt, while the starter activity of curd showed no difference among the three groups (P>0.05). Sensory evaluation of the products revealed that there was a negative correlation (P<0.05) between the sensory scores and SCC of milk. It was concluded that the milk with SCC greater than 5x105cells/ml had negative impact on the quality of milk and milk products. Estimation of DNA content of milk will provide a good technique for enumeration of SCC in milk.