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Anand Agricultural University, Anand
Anand Agricultural University (AAU) was established in 2004 at Anand with the support of the Government of Gujarat, Act No.(Guj 5 of 2004) dated April 29, 2004. Caved out of the erstwhile Gujarat Agricultural University (GAU), the dream institution of Sardar Vallabhbhai Patel and Dr. K. M. Munshi, the AAU was set up to provide support to the farming community in three facets namely education, research and extension activities in Agriculture, Horticulture Engineering, product Processing and Home Science. At present there seven Colleges, seventeen Research Centers and six Extension Education Institute working in nine districts of Gujarat namely Ahmedabad, Anand, Dahod, Kheda, Panchmahal, Vadodara, Mahisagar, Botad and Chhotaudepur
AAU's activities have expanded to span newer commodity sectors such as soil health card, bio-diesel, medicinal plants apart from the mandatory ones like rice, maize, tobacco, vegetable crops, fruit crops, forage crops, animal breeding, nutrition and dairy products etc. the core of AAU's operating philosophy however, continues to create the partnership between the rural people and committed academic as the basic for sustainable rural development. In pursuing its various programmes AAU's overall mission is to promote sustainable growth and economic independence in rural society. AAU aims to do this through education, research and extension education. Thus, AAU works towards the empowerment of the farmers.
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ThesisItem Open Access ASSESSING THE FEASIBILITY OF MANUFACTURE OF CONCENTRATED DAHI USING SELECTED STARTER CULTURES OF Streptococcus thermophilus AND Lactococcus lactis(AAU, Anand, 1997) PEERZADA, MEHRAJ-U-DIN; Sannabhadti, S. S.This study was planned and conducted to assess the feasibility of promising strains oi Streptococcus thermophihts, namely D-3 (C1) and MD-8 (C2) and Lactococcus lactis subsp. lactis strain C-10 (C3) in the manufacture of concentrated dahi from standardized milk adjusted to three different levels of total solids. For studying different attributes, concentrated cfahi was manufactured on pilot scale from standardized milk adjusted to 20.00(T1), 24.00(T2) and 28(T3) per cent total solids by fortification with skim milk powder. After standardization of these three lots of milk, they were heat treated to 90°C for 10 minutes and then cooled to room temperature. Starter culture was added as inoculum in each lot at the rate of 10 per cent based on preliminary studies. The inoculated milk of each lot was filled in polystyrene cups(100 ml capacity) having aluminium foil lids and then incubated at a temperature of 40±2°C in case of S/replococciis ihennophilus strains and 30+1 °C in case of Lactococcus lactis subsp. lactis strain. For assessing, chemical and microbiological changes during incubation, a set of cups from each lot of milk was drawn at 0, 4 and 8 hours interval. When the product attained an acidity of about 0.75-0.80 per cent lactic acid, a set of cups was transferred to the refrigerator and kept overnight. Next day product was subjected to the sensory evaluation by a panel of judges. Another set of cups was transferred to low temperature incubator maintained at a temperature of 10°C and the product was stored for 7 days at this temperature to know the acceptability of the product. T2 (24.00 per cent TS) level of total solids gave significant results than other level of total solids with respect to change in titratable acidity, extent of the lactose degradation, change in lactic count and utilization of soluble nitrogen during incubation with all the three strains. Among the cultures used, culture C1 showed higher acid production throughout the incubation period than C2 and C3, Dahi with desired level of titratable acidity was produced with C1 and C2 cultures within 4.0 hours of incubation. While it needed 8 hours with C3 culture. After storage of the product for 7 days at 10°C, C3, showed significant results with respect to change in titratable acidity, shift in pH, extent of lactose degradation, change in free fatty acids, changes in the soluble nitrogen and changes in lactic count indicating continued activity of culture even during refrigerated storage. Concentrated dahi was found veiy much acceptable even after 7 days of storage at al! levels of total solids with cultures C1 and C2. However, C3 produced bitterness in the product after 7 days of storage in T3 level of total solids and the product was unacceptable. Coliform count was found within prescribed BIS. limits of max. 10/g at the end of storage period. Same was also true with that of yeast and mold count which was within prescribed limit of max.100/g From the observations on uniform rate of acid production, lactose utilization and stability to higher concentration of total solids, it is possible to recommend all the three strains for the manufacture of concentrated dahi using standardized milk between 20 and 28 per cent total solids (TMS), Among the three strains, although all of them were capable of producing acceptable product within 6 hours of incubation, D-3 and MD-8 strains of Streptococcus thermophilus were found superior to C-10 strain of Lactococciis laciis as they could set the product within 4 hours and had better acceptability score even after 7 days storage at 10°C.ThesisItem Open Access STANDARDIZING CONDITIONS FOR PILOT SCALE PRODUCTION AND STORAGE OF BUFFALO MILK DAHI USING SELECTED STRAINS OF STREPTOCOCCUS THERMOPHILUS(AAU, Anand, 1991) Dave, Rajiv I.; Dave, J. M.This study was planned and conducted to evaluate the quality of household and market samples of dahi and to select the promising, local stable cultures for commercial manufacture of dahi with enhanced acceptability and stability. After preliminary trials, three strains of Streptococcus thermophilus viz., MD2 (C1), MD8 (C2) and D3 (C3) were selected for dahi manufacture- on pilot scale from whole buffalo milk adjusted to 15 (T1), 18 (T2) and 21 (T3) per cent level of total solids by way of adding condensed buffalo skim milk. The fat content of all the samples was maintained at 4.5 per cent. After standardization the three lots of milk were preheated to 60 C and then homogenized at a pressure of 100 kg/cm2 The homogenized lots were then subjected to a heat treatment of 85 C for 10 min and cooled to about 45 C. The standardized milk having individual level of milk solids was further divided into three equal parts. To each of these three lots MD2, MD8 and D3 starters were added as Inocula individually at the rate of 2 per cent (v/v). The inoculated milk samples were filled in polystyrene cups having lids and then incubated at 40 + 1 C , For assessing microbiological changes during incubation, the samples were drawn at 0, 2, 4 and 6 hours of incubation. For the purpose of storage studies, dahi cups were transferred to refrigerator (5-7 C) and held at that temperature for about 12 hours, End of this period was considered as 0 hour/0 day for storage studies. After this period of storage, half of the total samples of dahi were retained in the same refrigerator and remaining half were transferred to an incubator (37 + 1 C) . For assessing microbial changes in dahi at an ambient storage temperature (37 + 1 C), samples were drawn at 0, 12, 24 and 48 hours of storage, whereas, in case of refrigerated storage (5-7 C), Samples were drawn at 0, 6, 12 and 18 days of storage.ThesisItem Open Access PERFORMANCE EVALUATION OF STREPTOCOCCUS THERMOPHILUS STRAINS IN SKIM MILK DAHl MANUFACTURE WITH REFERENCE TO ITS MICROBIOLOGICAL AND KEEPING QUALITY(AAU, Anand, 1990) Saxena, Alok; Sannabhadti, S. S.This study was planned and conducted to evaluate the comparative performance of three promising strains of Streptococcus thermophiius, naraely D-3(C1), MD-2(C2) and MD-8(C.j) isolated from market samples of aahi, and to assess their feasibility for commercial manufacture of dahi from standardized buffalo skim milk adjusted to three levels of total solids. These strains grown in skim milk were also examined for their antibacterial ability against Escherichia coli, Staphylococcus aureus. Salmonella typhosa. Bacillus cereus and Pseudomonas aeruginosa. For studying different attributes, dahi was manufactured on pilot scale from buffalo skim milk adjusted to 1O.O(T1), 12.5(T2) and IS.OCT^) per cent total solids by addina condensed buffalo skim milk. After standardization of these three lots of milk, they were heat treated to 90 C for 10 min and then cooled to 40 C, The standardized milk, having individual level of milk solids, was divided further into three equal parts. To each of these, D-3,MD-2 and MD-8 strains were added as inoculum individually at the rate of 2 per cent. The inoculated milk sanples were filled in polystyrene cups having lids and then inoculated at 40 + 1 C.For assessing microbiological changes during incubation, a set of cups from each lot of milk were drawn at 0,2,4 and 6 hour periods. For analysis of skim milk dahi during storage, samples were transferred to a refrigerator (5 - 7 C) when the curd sanples attained an acidity of 0.75 per cent and kept overnight. End of this period was considered as 0 hour/day for storage studies. After this storage, half of the total samples of curd were retained in the refrigerator and remaining half were transferred to an incubator(37 + 1C), For assessing microbial changes in dahi at ambient temperature storage (37 4; 1 C), samples were drawn at 0, 12, 24 and 48h of storage and at 0, 6, 12 and 18 days in case of refrigerated storage (5 - 7 C), T, (15 per cent T.S.) level of total solids gave significant (P^O.GS) result than other level of total solids with respect to change in titratable acidity, shift in pH, extent of lactose degradation, change in lactic count and /B-galactosidase content during incubation with all the three strains, c2 and C3 showed higher acid production throughout the incubation period than C1 which took nearly 5.5h to form the product. Dahi with desired level of titratable acidity was produced with C and C3 cultures within 4.5 hours of incubation.During ambient and refrigerated temperature storage also, T- showed significant result (P 4 0,05) with respect to change in titratable acidity, shift in pH, change in lactic count, extent of lactose degradation, B-galactosidase content and standard plate count. Dahi showed a shelf life of 12 days at refrigerated temperature and only 24 h at ambient temperature Coliform count was found within prescribed BIS limit of Max, 10/g throughout the storage period while yeast and mold count was within prescribed limit of Max, 100/g, only upto 24 h in case of room temperature storage and 12 days at refrigerated storage, with dahi showing high count at 46 h and IC days at which period the product was unacceptable organoleptically. In the in-vitro study on antibacterial activity of the product, MD-2 culture showed maximal antibacterial activity among the three strains against Escherichia coli. Bacillus cereus. Staphylococcus aurevis cind Pseudomonas aeruginosa which was followed by MD-8. D-3 showed the least antibacterial activity and it was found to be mainly due to lactic acid. Antibacterial activity against Salmonella typhosa, however, was the highest with MD-8 followed by MD-»2 and D-3, From these observations it can be stated that in MD-2 and MD-8, the components other than lactic acid arealso involved in antibacterial activity. From the observations on uniform rate of acid production, lactose utilization, increase in lactic count, B-galactosidase to activity, etc., it is possible recommend all the three iv strains of S-, thermophilus for the manufacture of dahi using buffalo skim milk standardized between 10 and 15 per cent TS. Among the three strains, although all of them were capable of producing acceptable product within about 5,5 of incubation, MD-2 and MD-8 strains of S, thermophiluaverefound superior to D-3 strain as they could set the gel within 4.5h and have better antibacterial activity against pathogenic and spoilage organisms. The results of the study on B-galactosidase activity in the product made with the three strains show that the enzyme level was much higher in MD-2 and MD-8 cultures than D-3 culture. The concentration of this enzyme in D-3 culture was less than half of that observed with MD-2 or MD-8. However, looking to the high lactic count and almost similar Jactose degradation in D-3 culture it is thought that in this strain, the pathway adopted for lactose degradation was somewhat different than MD-2 and MD-8, In which permease system seems to be operative. -temperature. The product stored at ambient/was spoiled within 24 h while refrigerated storage kept the product for 12 days, so for better storage stability of the product, refrigerated storage is recommended Hence hi oh yeast and mold counts seem to be the cause for spoilage of the product, avoiding their entry and restricting their growth in the product is essential, for further enhancing the shelf life of the product.ThesisItem Open Access FAECAL MICROFLORA OF BREAST-FED INFANTS WITH SPECIAL REFERENCE TO PRESENCE OF BIFIDOBACTERIA(AAU, Anand, 1999) Acharya, Mayur R.; Shah, R. K.A study was planned and conducted with the following objectives: (i) to know the population of different groups of microorganisms present in faecal matter of breast-fed infants, (ii) to know the influence of method of delivery (normal or caesarian section) on the faecal flora of infants, (iii) to evaluate three media viz., Tryptone Phytone Yeast extract Agar (TPYA), Neomycin sulfate, Paromomycin sulfate, NaUdixic add. Lithium chloride Agar (NPNLA) and Lithium chloride Sodium propionate Agar (LPA) for their suitabiUty for enumeration and isolation of bifidobacteria from faeces, (iv) to isolate a few strains of bifidobacteria with probiotic potential and (v) to study in vitro tolerance of these selected isolates to low pH and also to grow in presence of bile and phenol so as to evaluate their capacity to grow under unfavourable conditions of the digestive tract and (vi) to study their growth characteristics in skim milk. Faecal samples from 15 breast-fed infants (9 from infants born through normal delivery and 6 from infants delivered by caesarian section) with age ranging from one week to six months were collected and analysed for bifidobacteria count (on TPYA, NPNLA and LPA), LactobadUi Count (LC), Faecal Streptococci Count (FSC), CoUform Count (CC), Aerobic Plate Count (APC), Total Anaerobic Count (TAC) and Anaerobic Spore Count (ASC). The counts of bifidobacteria (log cfu/g) ranged from 8.26 to 12.24 (average 10.69) on TPYA, 7.11 to 10.63 (9.06) on NPNLA and 5.86 to 9.63 (7.37) on LPA. The values for LC, CC, FSC, APC, TAC and ASC ranged from 6.28 to 9.69 (8.04), S.Sl to 9.99(7.65), 4.08 to 9.20 (6.39), 7.84 to 13.75 (10.48), 8.04 to 12.65 (10.20) and 3.80 to 7.11 (5.64) log cfu/g, respectively. On statistical analysis of data it was found that the differences between counts in the groups (i) infants with normal delivery and infants delivered by caesarian section as well as (ii) exclusively breast-fed infants and infants on mixed feeding, were not significant for any of the counts. The counts of bifidobacteria on three media differed significantly (P<0.05) from each other with count on TPYA being the highest, followed by NPNLA and LPA. For isolation of bifidobacteria, altogether 281 well isolated colonies were picked up from NPNLA, LPA and TPYA, purified and subjected to identification and characterization in two stages. The primary screening of the isolates was done by (i) morphological examination (Gram's staining), (ii) catalase test, (iii) litmus milk reactions, (iv) checking for gas production and v) spore formation. After primary screening, 36 typical isolates showing Gram positive reaction, negative catalase, litmus milk reactions like acid production, coagulation and reduction, no gas production and no spore formation were selected for further detailed biochemical characterization. The tests performed included: indole production, nitrate reduction, gelatin liquefaction, glycerol fermentation, urease production and various carbohydrate fermentation tests. All the isolates were unable to produce indole, reduce nitrate, liquefy gelatin, ferment glycerol and produce urease. Based on carbohydrate fermentation tests, 14 isolates were identified as B. bifidum and 12 were identified as B. breve. Remaining 10 isolates were placed under the category of Bifidobacterium sp. as the carbohydrate fermentation pattern of these isolates was matching with more than one bifidobacteria species. The isolates were checked for their tolerance to low pH, ability to grow in presence of various levels of bile and phenol. All the isolates could grow well at pH 5.0 and could survive pH 4.0 (except isolate 13 and 36). All the isolates could grow well in 1% bile and survive up to 3% bile concentration (except isolate 13 and 36). However, some isolates (8, 21 and 25) could survive even higher level (4%) of bile concentration. All the isolates were capable of growing in 0.2% phenol and could survive exposure to 0.3% phenol concentration. Moreover, isolates 8,21 and 25 could also grow in 0.3% phenol, but could not survive exposure to 0.4% phenol concentration. The growth characteristics of the isolates in milk were also studied in order to evaluate their suitability for use in fermented milk preparations. The viable count (log cfu/g) after 48 h of incubation ranged from 8.60 (isolate 19) to 11.89 (isolate 23) with an average of 10.42. The final pH obtained at the end of 96 h of incubation ranged from 4.33 (isolate 4) to 5.85 (isolate 36) with an average of 4.92. Similarly, the rate of acid development (% lactic acid) at the end of 96 h of incubation ranged from 0.49 (isolate 10) to 1.32 (isolate 4) with an average of 0.76.ThesisItem Open Access MICROBIOLOGICAL, CHEMICAL AND SENSORY ATTRIBUTES OF MARKET PANEER(AAU, Anand, 1996) Gohain, Haren Bura; SHAH, R. K.For the study 30 market paneer samples were collected from four urban markets and an organized dairy plant which also comprised of 18 different producers. All the samples collected were subjected to detailed microbiological as well as chemical analysis and also graded for various sensory attributes. The microbiological analysis for total count, coliform, yeast and mould, enterococci, psychrotrophs, mesophilic aerobic spore formers, acid producers, proteolytic and lipolytic counts indicated general mean values of 5.94, 3.34, 3.11, 3.67, 4.96, 2.80, 5.28, 5.06 and 3.95 log c.f.u./g respectively, which also reflected very poor microbial quality. The chemical analysis for moisture, fat, protein, lactose, acidity (per cent LA) and acid degree value, indicated general mean values 52.65, 23.27, 21.33, 2.59, 0.631 per cent and 1.30, respectively. None of the market paneer samples could comply with. overall prescribed BIS specifications and only 60 per cent could meet PFA requirements. Sensory evaluation of paneer samples through an expert parcel of judges revealed that flavour, body and texture, colour and appearance and total score obtained general mean values of 38.14, 27.74, 8.99 and 79.87, respectively. Correlation studies for microbiological, chemical and sensory attributes among themselves, and their interactions suggested that some of the microbiological and chemical parameters as well as all sensory attributes were showing good correlations among themselves. However, interactions of microbiological parameters with sensory and'chemical attributes were not significantly correlated due to perhaps fresh market samples.ThesisItem Open Access EFFECT OF HANDLING, THERMIZATION AND ACTIVATION OF LACTOPEROXIDASE SYSTEM ON MICROBIOLOGICAL QUALITY AND SHELF LIFE OF RAW BUFFALO MILK(AAU, Anand, 1992) Patel, Dilip Ambalal; Sannabhadti, S. S.The study was planned and conducted to study the effect of handling, thermization and activation of lactoperoxidase system on microbiological quality and shelflife of raw buffalo milk. the study on cow raw milk was taken for comparison. To study the effect of milk handling on its bacteriological quality, samples were collected from randomly selected individual milk producers at the point of milk collection, at RMRD of a dairy plant and from chilling centre of the dairy. To study the influence of LP treatment and thermization treatment, pooled raw milk samples were collected from Students Training Dairy. To study the sources of contamination, foremilk, middlemilk and dung samples wepe collected from buffalo herd of Reproductive Biology Research Unit. Can rinses samples were collected from randomly selected milk collection centres of a commercial dairy plant. Activation of LP system at the levels of 15:10 ppms (B)and 45:30 ppms (C) of SCN : H2O2, respectively, gave significant extension in shelflife of buffalo milk stored at 37°C. The former treatment gave extension in shelflife of 3 hours (total 8 hours) and latter gave 6 hours (total 11 hours) as compared to untreated raw milk which had the shelflife of 5 hours as judged by CoB test. LPS at three times higher level i.e. 45:30 ppms of SCN H2O2; failed to give proportional advantage as compared to 15:10 ppm level of SCN:H2O2, suggested by IDF. Thus, higher level of addition may not be necessary if the application of LPS is thought for procurement of unoooled raw milk. Treatment B and C showed predominantly bacteriostatic influence on raw milk flora upto 3 hours of activation of LPS. Acid producing bacteria, proteolytic bacteria, coliform bacteria and thermoduric bacteria exhibited varying response to LPS. B and C showed reduction in Log APC of about 3.72 and 3.63 cfu per ml respectively, in comparison to untreated buffalo raw milk which had 4.13 Log cfu per ml. However, proliferation of acid producing bacteria remained unchecked soon after 3 hours of incubation. Coliforitis were most sensitive among all groups of micro-organisms enumerated. At 0 hour, Log CC for B and C was 3.38 and 2.99 cfu per ml respectively as against 4.07 Log cfu per ml of untreated raw milk. Conforms also tended to multiply profusely from third hour of incubation. Proteolytic bacteria and thermoduric bacteria were found to be quite resistant to LPS. They tended to multiply significantly through the storage period. Thermization at higher temperature i.e. 65°C/20s as well as lower temperature of heating i.e. 60 C/20s did not give significant enhancement in shelflife in comparison to untreated milk.However, there was marked arrest of acidity in treated milks upto 3 to 4 hours as compared to untreated raw milk. Successive thermization followed by LP (ExC) with sensitisation at 37 C for two hours, showed significant arrest of acidity in cow milk as compared to C alone however, in case of buffalo milk, ExC and C were comparable. It was observed that milkers hands, teat surfaces and / or interior of the udder could be some of the important initial sources of contamination because milk samples collected using sterilized containers also showed SPC of more than 10 cfu per ml and CC more than 3 10 to the power 3 cfu per ml. Rinsing of milk cans with potable water prior to addition of milk may be useful because this step followed in the study reduced the bacterial load by about ten times. Similar care about the coat and hind quarters of the animal is very important because falling of even 1 gm dung may contribute as high as 10 bacteria. If care can be exercised to preclude above dominant sources of contamination, shelflife of LP activated milk can be further improved. From the results of this study , it can be indicated that thermisation alone or in combination with LP treatment has no real practical advantage over LP treatment alone under the conditions existing in our country. So LP treatment alone, at the level suggested by IDF or at three times higher concentration suggested by Thakar and Dave (1986) can be recommended under our conditions of raw milk procurement for both cow and buffalo milk to extend its shelflife.ThesisItem Open Access EVALUATION OF HYPOCHOLESTEROLEMIC EETECT OF DIETARY LACTOBACILLI(AAU, Anand, 1997) ASHAR, MANISHA N.; Prajapati, J. B.A high level of cholesterol in blood, a major risk factor in the occurrence of coronary heart diseases, can be reduced through dietary means. Consumption of fermented milks have shown potential as cholesterol reducing agents. This study was taken up to verify hypocholesterolemic effect of selected strains of lactobacilli through in vitro and in vivo methods. Four strains of lactobacilli viz. Lb. acidophilus H3, V3 and C2 and Lb. casei I4 were initially tested for bile tolerance, bile deconjugation, cholesterol assimilation and antibacterial activity in vitro. The strain V3 gave a good overall performance in all these tests and was hence selected for the in vivo feeding trials. Twenty seven volunteers having either primary or secondary hyperlipemia as well as volunteers with normal health were included in the in vivo trial. Their blood samples were analyzed for lipid profile twice prior to, during and after feeding 200 ml of acidophilus lassi per day for 20 days, keeping a gap of 10 days between two collections. On statistically analyzing the heterogeneous raw data, a significant (P<0.05) reduction from 210 mg/dL to 194 mg/dL (7.6 percent) in total cholesterol and from 133 mg/dL to 112 mg/dL (15.7 percent) in the LDL cholesterol values was noticed over the study period. Grouping of volunteers on the basis of sex, age, initial cholesterol level, health status and dietary habits included sex groups, males (M) and females (F); three age groups, 20-40 years (A,), 40-60 years (A2) and 60-80 years (A3); four groups based on initial cholesterol level, <200 mg/dL (C1), 200-220 mg/dL (C2), 220-250 mg/dL (C3), >250 mg/dL (C4); four health groups consisting of normal health individuals (H,), hypertensive subjects (H2), subjects having hypothyroidism (H3) and diabetes (H4); and two dietary habit groups, vegetarians (V) and non-vegetarians (NV). A significant reduction (P<0.05) in the total cholesterol values in A1, C2, C3 and H, groups by 11.7, 21.0, 12.4 and 16.4 percent, respectively was noticed. The average serum triglycerides increased in groups Gj, H4 and V. The average HDL cholesterol level remained unchanged except in A, and A2 groups where some temporary reduction was observed. The average serum VLDL cholesterol increased in groups G|, H4 and V. The average LDL cholesterol level showed a significant reduction (P<0.05) in the group G2 from 132 mg/dL to 78 mg/dL (41 percent). Ratios of LDL/HDL cholesterol and total/HDL cholesterol reduced significantly from 3.1 to 2.4 and 4.9 to 4.3, respectively in the Aj group. Trend analysis of the raw data of 27 volunteers indicated a significant trend of quadratic decline in the LDL cholesterol values. The grouped data showed a linear trend of continuous decline in M, F, H, and H4 groups with respect to the average total cholesterol level over the time periods, whereas a quadratic trend fitted with A1, A2, C1, C2, C3, V and NV groups. The average triglycerides level showed a significant linear trend (P<0.05) of increase in A3 group, whereas in A2 and C1 groups, a significant quadratic trend was observed. In the average HDL cholesterol level, a non-significant quadratic trend of decline was seen in A1 group. The average VLDL cholesterol values showed a significant quadratic trend of increase in groups A2, C1 and A3 group, A linear significant (P<0.05) trend of continuous decline in average LDL cholesterol was observed in F and A2 groups of volunteers, whereas a quadratic trend of decline in M, A1, A3, C2, C3, C4, H2, H4, V and NV groups was found. The average LDL/HDL and total/HDL cholesterol ratios showed a significant (P<0.05) linear trend of continuous decline in females and quadratic trend in A1 and H4. The C2 group showed a significant linear trend (P<0.05) of decline in average LDL/HDL cholesterol ratio and quadratic trend of decline in Total/HDL cholesterol ratio. In the group H3, neither of the two trends fitted with any lipid profile parameter over entire study. The feeding had maximum effect on serum total cholesterol and least effect on HDL fraction. In most cases, the significant reduction in lipid profile parameter continued upto 20 days post feeding, indicative of a residual effect. The feedback from volunteers was encouraging.ThesisItem Open Access ENUMERATION OF MESOPHILIC AEROBES, COLIFORMS, SULPHITE REDUCERS AND ANAEROBIC SPOREFORMERS IN RAW AND PASTEURIZED MILK(AAU, Anand, 1991) Chepuru, Venkata Siva; Sannabhadti, S. S.An attenpt has been nade to study the changes in nicrobiological quality of raw milk at various stages of milk collectionfWith an intention to find out the sources for addition of various groups of microorganisms and the differences in microbiological quality of cow and buffalo milk, if any. Special emphasis was on the study of incidence of anaerobic sporeformers in milk at these stages of milk production, collection and handling. Pasteurized milk samples were also analysed for incidence of anaerobic sporeformers, along with other groups of microorganisms. Just after processing. With a view to pinpoint the major sources of contamination of raw milk with anaerobic sporeformers and other groups of microorganisms, samples of fore milk and middle milk, milk can rinses and dung were examined for the incidence of these groups. The correlation existing among various groups of microorganisms was also calculated to know the co-incidence of various groups studied. Samples of raw cow and buffalo milk were collected from randomly selected individual producers, collection centres, and a commercial dairy plant. Bulk milk being sent to the commercial dairy plant from chilling centres was also sampled. Samplers of pasteurized milk were collected from the Students' Training Dairy, S.N.C. College of Dairy Science. Anand, Gujarat, within 30 minutes of processing. Fore milk, the first five streams from each teat, and the middle milk samples were collected from aii university farm, Gujarat Agricultural University, Anand. Fresh dung samples were also collected from the buffalo farm and milk can rinses from collection centres and an university dairy farm supplying milk to the commercial dairy plant. Samples were tested for the incidence of anaerobic sporeformers using two methods namely Sulfite Reducing Clostridial Spore Count and Presumptive C. perfringena count using (Egg - Yolk free) Tryptose - Sulfite - Cycloserine Agar, Mesophilic Aerobes namely coliforms, acid producers, total microorganisms and mesophilic aerobic spores.ThesisItem Open Access STANDARDIZING CONDITIONS FOR PILOT SCALE PRODUCTION AND STORAGE OF COW MILK DAHI USING STREPTOCOCCUS THERMOPHILUS STRAINS AS STARTER CULTURE SOME MICROBIOLOGICAL ASPECTS(AAU, Anand, 1990) Kumar, Rakesh; Dave, J. M.This study was planned and conducted to evaluate the comparative performance of three promising strains of Streptococcus thermophilus namely D-3 (C,), MD-2 (C2) and MD-8 (Cg) isolated from market samples of dahi and to assess their feasibility for commercial manufacture of dahi from standardised cow milk, adjusted to three levels of solids. These strains were also examined for antibiotic sensitiveness and their antibacterial ability against various food poisoning and spoilage microorganisms. for studying - different attributes, dahi was manufactured on pilot scale from whole cow milk adjusted to 12 (T1), 15 (T2) and 18 (T3) per cent total solids by adding condensed cow skim milk. The fat content in these milks were maintained at 3 per cent. After standardization these three lots of milk were preheated to 60°C and then homogenized at a pressure of 140.7 kg/cm2 in a single stage homogenizer. The homogenized lots of standardized milk were preheated to 85°C for 15 min and then cooled to 40°C. The standardized milk having individual level of milk solids was divided further into three equal parts. To each of these D-3, MD-2 and MD-8 strains were individually added as inoculum at the rate of 2 per cent. The inoculated milk samples were filled in polysterene cups having lids and then incubated at 40 ± 1°C. Por assessing microbiological changes during incubation, a set of cups from each lot of milk were drawn at 0, 2, 4 and 6 hour periods. For analysis of cow milk ,dahi during storage, samples were transferred to refrigerator (5-7°C) when the curd samples attained an acidity of 0.70 per cent and kept for about 12 hour. The starting of storage period at 37°C and in the refrigerator was considerate the end of 12 hour period indicated above. For assessing microbial changes in dahi at ambient temperature of storage (37 ± 1°C) the samples were drawn at 0, 12, 24 and 48 hours of storage and in case of refrigerated storage (5-7°C) at an interval of 0, 6, 12 and 18 days of storage. To (18 per cent T.S.) level of total solids gave significant (P < 0.05) result than other level of total solicJs with respect to change in titratable acidity, shift in pH, extent of lactose degradation, change in lactic count and 6-ga lactosidase content, during incubation with all the three strains. C2 and C3 showed higher acid production upto 4 hour than C1 and dahi with desired level of titratable acidity can be produced with these two cultures within . 4.5 hr of incubation. C2 gave highest g-galactosidase activity followed by C3 and it was lowest with C1 culture . During ambient and refrigerated temperature storage also T3 showed significant (P< 0.05) result with respect to change in titratable acidity, shift in pH, change in lactic count, extent of lactose degradation, B-galactosidase content and standard plate count. Dahi showed a shelflife of 12 days at refrigerated temperature and only 24h at ambient temperature, coliform count was found within the limit throughout the storage while yeast and mold showed a count within prescribed limit only upto 24h in case of room temperature and 12 days at refrigerated storage, with products showing high count after 48h and 18 days at which period it was not acceptable organoleptically. Among the three strains which were used in this study, MD-2 showed higher resistance to a number of antibiotics compared to MD-8 and D-3. however, all three strains to be were found /resistant: to penicillin, carbenicillin and nalidixic acid.