EFFECT OF ANTIOXIDANT PRINCIPLES ISOLATED FROM TUlSl (Ocimum sanctum Linn.) LEAVES ON OXIDATIVE STABILITY OF GHEE

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dc.contributor.advisorSHARMA, R. S.
dc.contributor.authorSHARMA, MAMTA
dc.date.accessioned2018-05-16T04:08:53Z
dc.date.available2018-05-16T04:08:53Z
dc.date.issued1997
dc.description.abstractA study was carried out to elucidate the effect of addition of antioxidant principles of Tulsi (Ocimum sanctum Linn.) leaves via a pre-extract on oxidative stability of ghee. The leaves identified as of Sri Tulsi and Krishna Tulsi were collected separately from the herbs available within the vicinity of Anand Campus of Gujarat Agricultural University. The antioxygenic compounds of Tulsi leaves were extracted into methanol. After vacuum drying it was fractionated into water soluble (WSF) and water insoluble (WISP) fractions. The WISP exhibited good antioxidant properties, whereas pro-oxidant properties resided mostly in the WSF. The WISP was treated with activated silica gel and charcoal mixture to remove colour imparting pigments and designated as SCF. The Sri Tulsi leaves powder and Krishna Tulsi leaves powder, respectively, contained on an average 8.80 and 6.82 per cent moisture plus volatile oil, 0.78 and 1.24 per cent volatile oil, 8.02 and 5.58 per cent moisture (by difference), 15.87 and 15.67 per cent alcohol soluble extract, 27.07 and 30.93 per cent cold water soluble extract, 2.80 and 3.20 per cent non-volatile extract, 2.91 and 2.84 per cent petroleuin ether (40-60 °C) extract, 12.59 and 11.44 per cent total ash, 21.78 and 20.34 per cent protein and 9.56 and 10.28 per cent crude fibre. All the fractions of TLP were analysed for total phenolics and phospholipids. Sri Tulsi leaves powder contained on dry matter basis, total phenolics as 108.57 mg/g of methanol extract (1.451 per cent of TLP), 46.96 mg/g of WSF (0.526 per cent of TLP), 56.67 mg/g of WISF (0.834 per cent TLP), 107.53 mg/g of SCF (0.379 per cent of TLP), while phospholipids content was 0.032 mg/g of methanol extract (0.0031 per cent of TLP), whereas, other fractions contained no dclcclabic amoiinl of phospholipids. Krishna Tulsi leaves powder contained on dry matter basis, total phenolics as 166.71 mg/g of methanol extract (1.667 per cent of TLP), 88.64 mg/g of WSF (0.913 per cent of TLP), ), 69.79 mg/g of WISF (0.621 per cent of TLP), 154.13 mg/g of SCF (0.337 per cent of TLP), while phospholipids content was 0.050 mg/g of methanol extract (0.0030 per cent of TLP), however, no estimatable amount of phospholipids was present in all the fractions studied. Fresh ghee manufactured at Vidya Dairy, G.A.U., Anand, by creamery butter method employing pre-stratification process and clarified at 110°C without any holding time was used in the study. Tulsi leaves powder and all the other fractions viz. methanol extract, WSF, WISF and SCF were evaluated for their effectivity against oxidative deterioration of ghee. In all the trials, the samples were analysed for peroxide value after an interval of 48 h at 80 ± 2 °C. In order to evaluate the relative effectiveness of the additives at different levels the induction period (hours required to reach a peroxide value of 5 meq. of peroxide oxygen per kg) of ghee samples were determined. To understand further the effect of such additions, the antioxidant indexes (protection factors) were calculated as the ratio of the induction period of the treated sample to the induction period of the control. A comparison was made between antioxygenic effectiveness of Sri Tulsi leaves and Krishna Tulsi leaves, SCF pre-extract. Krishna Tulsi leaves exhibited slightly higher antioxygenic activity as compared to Sri Tulsi leaves and hence used for all further studies. The SCF pre-extract of Krishna Tulsi leaves was added to ghee at the rate of 0.0 (T0, control), 0.2 (T1), 0.4 (T2) and 0.6 (T3) per cent (w/v) levels constituting different treatments. For comparison the last treatment was addition of butylated hydroxy anisole (BHA) at the legally permitted rate of 0.02 per cent (T4). All the treated samples were kept at 40 ± 2 °C for 1 h, then temperature was raised to 50 ±2 °C for half an hour. Ghee samples were decanted to remove sediments and immediately transferred to a memmert type oven maintained at 80 ±2 °C for accelerated storage studies. The water extractable phenolic content of treated ghee samples added with SCF pre-extract was in the order : 7.786 mg/g (T3) >5.008 mg/100g (T2) > 2.165 mg/100g (T1) > 0.748 mg/100g (T4) > 0.738 mg/100g (T0).No estimatable amount of methanol extractable phenolics was detected in control ghee, while for other treatments the order being : 53.799 mg/100g (T3) > 21.796 mg/l100g (T2) > 12.429 mg/100g (T1) > 8.464 mg/100g (T4). The antioxygenic indexes were in order : 1.90 (T3) > 1.60 (T4) > 1.54 (T2) > 1.35 (T1) > 1.00 (T0). From the results of this study, it was concluded that the antioxygenic compounds of Tulsi leaves can be extracted in methanol and further isolated in the form of SCF. Addition of these antioxygenic compounds as SCF pre-extract enhanced the oxidative stability of ghee. Addition of SCF pre-extract at the level of 0.6 per cent (w/v) was found to be more effective than the addition of BHA at the level of 0.02 per cent. The phenolics present in the Tulsi leaves appeared to be the main contribution factors in enhancing the oxidative stability of ghee. Paper chromatographic studies performed on all the fractions also revealed the presence of phenolics. Besides these compounds beta-carotene, saponins, sterols, eugenol, methyl eugenol, phospholipids and carbohydrates present in Tulsi could be responsible for antioxygenic effect observed.en_US
dc.identifier.urihttp://krishikosh.egranth.ac.in/handle/1/5810046195
dc.keywordsEFFECT OF ANTIOXIDANT PRINCIPLES, ISOLATED FROM TUlSl (Ocimum sanctum Linn.), LEAVES ON OXIDATIVE STABILITY OF GHEEen_US
dc.language.isoenen_US
dc.publisherAAU, Ananden_US
dc.research.problemEFFECT OF ANTIOXIDANT PRINCIPLES ISOLATED FROM TUlSl (Ocimum sanctum Linn.) LEAVES ON OXIDATIVE STABILITY OF GHEEen_US
dc.subDairy Chemistryen_US
dc.subjectDAIRY CHEMISTRYen_US
dc.subjectA STUDYen_US
dc.themeEFFECT OF ANTIOXIDANT PRINCIPLES ISOLATED FROM TUlSl (Ocimum sanctum Linn.) LEAVES ON OXIDATIVE STABILITY OF GHEEen_US
dc.these.typeM.Scen_US
dc.titleEFFECT OF ANTIOXIDANT PRINCIPLES ISOLATED FROM TUlSl (Ocimum sanctum Linn.) LEAVES ON OXIDATIVE STABILITY OF GHEEen_US
dc.typeThesisen_US
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