Browsing by Author "SHARMA, R. S."
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ThesisItem Open Access CARRY-OVER AND STATUS OF AFLATOXIN M1 IN MILK AND MILK PRODUCTS(AAU, Anand, 1995) LAL, PEETAM; SHARMA, R. S.The survey on status of aflatoxin M1 in milk of individual animals and market milk was carried out in and around Arsaiid town. Out of 223 milk samples analysed, 210 (94.17%) samples were found contaminated with aflatoxin Mi. The aflatoxin Ml content in positive samples ranged from 0.006 to 0.763 jig per 1 with an average of 0.097 ± 0.001 \ig per 1. All the bulk milk sanpies contained aflatoxin Mi bslcw the action level of Food and Drug Administration (0.50 µg/l). Only a few samples of milk from the individual cows exceeded the said limit. The carry-over study of aflatoxin Bi from naturally contaminated rations to milk as aflatoxin M1 was studied, in 10 Indian cows divided into five groups of two cows under each, at aflatoxin Bi intake levels of 12.50 (Control), 25.00 (T1), 52.53 (T2), 77.90 (T3) and 108.45 (T4) µg per kg of ration. The experiment was conducted in three phases, each phase comprised of seven days feeding. Feeding of aflatoxin B1 contaminated rations to the cows reduced feed intake and nilk yield. However, such effects were non significant. The effects were more pronounced at higher levels and long term feeding. The aflatoxin M1 content in milk increased significantly (P < 0.05) as the level of aflatoxin Bi increased in the diet. The average values for aflatoxin M1 content in milk of the cows during the feeding period was 0.04, 0.08, 0.14, 0.36 and 0.65 µg per 1 for Control,, T1, T2, T3 and T4 respectively. Carry-over rate of aflatoxin Bi from feed to milk as aflatoxin Mi increased significantly (P < 0.05) with increased ingestion of aflatoxin Bi by the cows. The per cent conversion of aflatoxin Bi to aflatoxin M1 was 0.32, 0.48, 0.52, 0.60 and 1.03 for Control T1, T2, T3 and T4 respectively. The carry-over rate was high in high yielders and low in the low yielders. Feeding of the rations containing more that 77.90 y.g aflatoxin Bi per kg ration led to secretion of milk containing more than 0.50 ug aflatoxin M1 per 1, thus exceeding the present Food and Drug Administration limit. Chemical composition of milk viz. fat, protein, lactose and SNF was not affected significantly at any level of aflatoxin Bi intake during the experiment. However, some what reduction in fat and protein content was observed. No appreciable reduction in aflatoxin M1 content of naturally contaminated milk was observed during chilling and cold storage (5°C, 24h), batch pasteurization, HTST pasteurization and pre-heating, whereas, 14.5 and 12.21 per cent reduction was observed during boiling and eterilisation respectively. Similarly, 19.38 per cent reduction in the toxin content was observed during khoa making, while fermentation of milk using L. acidophilus, S. thermophilus and S.. laotis plus S. cremoris. during preparation of dahi from the aflatoxin Mi contaminated milk, a reduction of 29.33 to 57.66 per cent toxin was observed and the mixed strain starter culture gave maximum reduction in the toxin content. Evaluation of partitioning behaviour of aflatoxin Mi during preparation of milk products like chakka, paneer, casein, Cheddar cheese and Swiss cheese from the naturally contaminated milk indicated that maximum amount of toxin goes with these products. The enrichment factors for these products were 3.30, 2.57, 4.22, 3.15 and 4.98 times, respectively. On separation of aflatoxin M1 contaminated whole milk into skim milk and cream, the distribution, of the toxin was 69.13 and 30.87 per cent in skim milk and cream respectively.ThesisItem Open Access CHAKKA AS A SUBSTRATE FOR AFLATOXIN PRODUCTION BY Aspergillus parasiticus(AAU, Anand, 1992) TRIVEDI, KALPESH R.; SHARMA, R. S.Buffalo skim milk containing on an average 0.3 per cent fat and 11.02 per cent solids-not-fat was used for preparation of chakka. The steps followed for chakka making were : Preheating of buffalo milk to 40°c, separation in centrifugal separator, heating of skim milk at 85°C for 15 min, cooling to 42°C, adding Streptococcus thermophillus-MD2 as strarter culture at the rate of 2.5 per cent, ripening till 1 per cent acidity and draining out the whey to get the final product. The chakka so prepared contained 75.04 per cent moisture, 1.20 per cent fat, 17.97 per cent protein, 2.47 per cent total reducing sugar and 24.96 per cent total solids. The product was evaluated as a substrate for mould growth and aflatoxin production by Aspergillus parasiticus ATCC-15517 through artificial inoculation.ThesisItem Open Access EFFECT OF ANTIOXIDANT PRINCIPLES ISOLATED FROM TUlSl (Ocimum sanctum Linn.) LEAVES ON OXIDATIVE STABILITY OF GHEE(AAU, Anand, 1997) SHARMA, MAMTA; SHARMA, R. S.A 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.ThesisItem Open Access EFFECT OF CASEIN LACTOSE AND CASEIN-LACTOSE MIXTURE ON OXIDATIVE STABILITY OF GHEE(AAU, Anand, 1981) MEGHA, ASHOKKUMAR VINUBHAI; SHARMA, R. S.The present study was carried out to elucidate the effect of casein, lactose and casein-lactose mixture (1:1) on the oxidative stebility of ghee. Ghee was prepared from butter obtained from fresh raw buffalo milk. The butter was clarified into ghee at 120°C without any holding time. Each additive namely, casein, lactose and casein-lactose misture was added to butter during its clarification into ghee at the levels of 2.5 and 5.0 per cent on the basis of fat content of butter. To compare the antioxidant properties of the above additives with synthetic antioxidant, butylated hydroxy anisole (BHA) was added at 0.01 and 0.02 per cent directly into ghee.ThesisItem Open Access EFFECT OF MANGO (Mangifera indica Linn.) SEED KERNELS ON OXIDATIVE STABILITY OF GHEE(AAU, Anand, 1984) Parmar, Shantilal Shibabhai; SHARMA, R. S.A study was carried out to clucidate the effect of addition of mango seed kernels (MSK) or its pre-extract on the oxidative stability of ghee. A composite sample of mango seed kernels powder (MSKP) prepared from the kernels of raw and ripened mangoes of various varieties available in the area contained 4.80 per cent moisture, 6.74 per cent protein, 12.96 per cent lipids, 2.19 per cent ash and 73.31 per cent carbohydrates as the major constituents and 6.39 per cent total phenolics, 575.5 mg per cent phospholipids and 0.85 per cent flavanols.ThesisItem Open Access PHYSICO-CHEMICAL AND STORAGE CHARACTERISTICS OF BISCUITS DEVELOPED FROM THE BLENDS OF CASEIN-WHEY PROTEIN COPRECIPITATES AND PARTIALLY DEOILED GROUNDNUT MEAL(AAU, Anand, 1986) PATEL, SOMABHAI MAGANLAL; SHARMA, R. S.This study was planned to develop a simplified process for preparation of partially deoiled groundnut meal (PDGM) with minimum possible mitty/bitter flavour inherent to groundnut and to make use of such meal in formulation of biscuits with blends of casein-whey protein coprecipitates (CWC) with a view to enhance protein-calorie value with out extraneous incorporation of hydregenated fat. This study also aimed to evaluate the impact of the above blends on the compositional, physico-chemical, organoleptic and storage characteristics of such biscuits and to suggest a simple process line for the manufacture of acceptable type of protein-calorie enriched biscuits with reasonable shelf-life.ThesisItem Open Access PHYSICO-CHEMICAL AND STORAGE CHARACTERISTICS OF BISCUITS DEVELOPED FROM THE PAPAIN MODIFIED BLENDS OF CASEIN-WHEY PROTEIN COPREClPITATES AND PARTIALLY DEOILED GROUNDNUT MEAL(AAU, Anand, 1988) PATEL, AJAY C.; SHARMA, R. S.this study was undertaken to assess the effects of partial hydrolysis of the proteins of partially deoiled groundnut meal (PDGM) and casein-whey protein coprecipitates (CWC) with papain on the physico-chemical and storage chara cteristics of the biscuits prepared by using such mixture in biscuit doughs, The PDGM was prepared by soaking the whole groundnuts in dilute alkali, removal of red skin through mechanical scrubbing and subsequently passing the deskinned kernels at appropriate moisture level through screw press and finally pressure cooking (115°C at 105 Pa for 5 min). The PDGM samples on an average contained 6.24 + 0.72 per cent moisture, 32.73+0.63 per cent protein, 43.80 + 1.93 per cent fat, 2.l6 + 0.10 per cent ash and 15.07 + 0.92 per cent total carbohydrates. The trypsin inhibitor activity of the raw materia reduced from 4.66 TIA units to 1.05 TIA units on pressure cooking.ThesisItem Open Access PHYSICO-CHEMICAL AND STORAGE CHARACTERISTICS OF WHEY-BANANA PULP POWDER(AAU, Anand, 2000) SHARMA, PRABHAT KUMAR; SHARMA, R. S.The study was planned to develop a simplified process for preparation of whey powder from cheddar cheese whey and whey banana pulp powder from lactose crystallized (LC) whey concentrate : processed banana pulp (75:25, 50:50 ratio by weight) respectively using tray drying method. The steps involved in the preparation of powders were: straining of cheddar cheese whey through muslin cloth, pasteurization (63°C/30 min) of whey, concentration (55 % TS) in vacuum pan (365 mm Hg. 55-56°C), cooling (30°C), seeding with lactose monohydrate @ 0.1 per cent, cooling to 5 to 6°C (by lowering the temperature @ 3°C for 6 h with agitation), and further holing at 5 to 6°C for 10 to 12 h to obtain lactose crystallized (LC) whey concentrate. This was divided into two lots. The first lot was used directly to prepare whey powder and the other lot was mixed with processed banana pulp (75:25 or 50:50 ratio by weight) prepared from banana fruits by peeling, cutting, adding water @ 1 to 1.5 %. pulping, heating (85°C / 5 rain) and cooling 45°C. Whey concentrate - banana pulp blends (35-40 % TS) were used to prepare whey banana pulp powders by following the steps viz: neutralization of blends with NaHCO3 ( 1% solution) and homogenization (38-40°C. 50 bar), tray drying (80-82°C / 4 h), grinding and sieving (355μm size) and then packing (HDPE laminate pouches) and heat sealing.ThesisItem Open Access PHYSICO-CHEMICAL CHANGES IN THE MAJOR MILK CONSTITUENTS DURING MANUFACTURE OF KHOA FROM LACTOSE HYDROLYSED BUFFALO MILK(AAU, Anand, 1981) SAI, PRAKASH BHASKARBHAI; SHARMA, R. S.This study was undertaken to cases the applicability of β-D-galactosidase in buffalo milk for hydrolysis of lactose and to assess the feasibility of lactose hydrolysed milk for the manufacture of khoa. The suitability of lactose hydrolised milk for khoa making was assessed by analysing the product for different physico-chemical changes during manufacture and storage of the same. Buffalo milk was treated with lactozyme (Novo industries, Den mark) to obtain lactose hydrolysed milk and khoa was prepared in the laboratory by the indigenous method of open pan desiccation. The khoa prepared from lactose hydrolysed milk was compared with the control khoa prepared from buffalo milk but without hydrolysis of lactose. The milk and khoa samples prepared from lactose unhydrolysed and lactose hydrolysed milk were analysed for composition, chemical characteristics, change in the composition of casein, electrophoretic resolution of casein, 1-fluoro-2,4-dinitrobenzene (FDNB) reactive and 2,4,6-trinitrobenzenesulphonic acid (TNES) reactive lysine content in casein and trichloroacetic acid precipitable proteins. The khoa was also assessed for its storage qualities.ThesisItem Open Access Some Physico-chemical and Storage Characteristics of Filled Milks(AAU, Anand, 1988) PATEL, DADHICH MANEKLAL; SHARMA, R. S.This investigation was carried out to elucidate the effects of fortification of buffalo skim milk with vegetable oils namely groundnut oil (GNO), cottonseed oil (CSO), soyabean oil (SBO,) and their mixture (MO) in equal proportion (v/v/v) to contain 5 per cent fat and compare the physico-chemical and storage characteristics of the resultant filled milks (SFM) with the standardized buffalo milk (SBM) containing similar level of milk fat and subjected to identical condition of heat treatment (80°C with no holding) both when fresh and on storage (5° to 7°C) for a period of 8 days. The refractive indices, the saponification and the iodine values of GNO, CSO, SBO and MO were 1.4674, 1.4586, 1.4608 and 1.4638; 193.42, 192.27, 199.45 and 196.62; and 92.03, 104.98, 133.55 and 110.72 respectively. Whereas the free fatty acids (per cent oleic acid) and peroxide values (meq of peroxide oxygen/kg oil) were 0.334, 0.162, 0.197 and 0.270 and 1.72, 1.28, 2.50 aid 1 .93 respectively. The chemical composition of the SBM and the SPM samples revealed that t o t a l solids content varied between 15.03 + 0.38 t o 15.18 + 0.33 per cent; fat between 5.00 + 0.02 to 5.10 + 0.03 per cent; protein between 4.29 + 0.22 t o 4.34 ± 0.23 per cent; lactose between 4.95 + 0.13 t o 4.98 + 0.11 per cent and ash between 0.79 ± 0.03 to 0.83 + 0.03 per cent. The acidity (per cent lactic acid) values of the fresh SBM, SPM-GNO, 3FM-C30, 3PM-SB0 and SPM-MO samples were 0.175, 0.170, 0.170, 0.170 and 0.170 whereas the pH values were 6.610, 6.625, 6.635, 6.637 and 6.635 respectively . The viscosity values (cP) of the fresh SBM, SPM-GNO, SPM-CSO, SPM-SBO and SPM-MO samples were 1.835 + 0.056, 1.953 + 0.051, 1.945 + 0.052, 1.978 +0.072 and 1.941 + 0.047 respectively.The creaming ability (per cent fat retained in the bottom portion of sample on storage under refrigeration conditions for 24 h) values for the SBM, SM-GNO, SM-CSO, 3M-3B0 and SM-MO samples were 2.24 + 0.20, 3.50+ 0.18, 3.25 + 0.18, 3.4-9 + 0.19 and 3.34 + 0.15, per cent respectively whereas the values for average loss of fat in the acid whey samples were 0.306, 0.026, 0.028, 0.024 and 0.025 per cent respectively. The tyrosine values (µ/ml sample) in the fresh samples (reaction stopped immediately on euidition of trypsin solution) of SBM, SPM-GNO, SPM-CSO, SFM-SBO and SFM-MO were 499.40, 529.39, 495.52, 488.29 and 483.29 respectively which on incubation with standard trypsin solution for one hour increased to 1275.60, 1266.54, 1235.43, 1206.00 and 1213.22 respectively. The average rennet clotting time for the SBM, SFM-GN0, SFM-CSO, SFM-SBO and SFM-MO were 326.84, 511.67, 472.50, 453.17 and 474.00 sec respectively. During storage (5° to 7°C) the changes in the status of chemical parameters namely acidity , pH, proteolysis ,' free fatty acids, thiobarbituric acid values and the microbial counts namely the total bacterial count and the psychrotropic counts were monitored at 4 days interval upto the 8th day of storage only. The acidity values (per cent, lacticacid) in the fresh SBM, SPM-GNO, SFM-CSO, SPM-SBO and SFM-MO recorded on the 0th day of storage were 0.175, 0.170, 0.170, 0.170 and 0.170 which rose to 0.207, 0.199, 0.200, 0.192 and 0.195 respectively on the 8th day of storage whereas the initial pH values of 6.610, 6.625, 6.635, 6.637 and 6.635 declined to 6,330, 6,355, 6.342, 6.362 and 6.352 respectively on the 8th day of storage. The free tyrosine values µg/ml sample) estimated in the fresh (0th day) samples of SBM, SM-GNO, SFM-CSO, SM-SBO and SM-MO were 427.84, 405.08, 400.92, 397.25 and 400.92 which increased to 586.70, 579.38, 578.37, 576.93 and 560.70 respectively on the 8th day of storage. The free fatty acids contents (meq/100 ml sample) of the SBM, SFM-GNO, SFM-CSO, SFM-SBO and SFM-MO estimated on, the 0th day were 1.834, 1.271, 1.042, 1.145 and 0.980 which increased to 2.084, 1.667, 1.271, 1.500 and 1.334 respectively on the 8th day of storage. The thiobarbituric acid (TBA) values (O.D. measured at 535 nm) of the SBM, SFM-GNO, SFM-CSO, SFM-SBO and SFM-MO on the 0th day of storage were 0,081, 0.099, 0.092, 0.140 and 0.120 which increased to 0.135, 0.168, 0.153, 0.200 and 0.170 respectively on the 8th day of storage.