Cow Milk Yogurt Research Articles

Propiedades fisicoquímicas y aceptabilidad sensorial de yogur de leche descremada de cabra frutado con mango y plátano en pruebas aceleradas

Two types of skimmed (fat 3%) goat’s milk fruit yogurt with mango (YM) and banana (YB) were stored at temperatures of 5 °C, 15 °C and 25 °C for 72 hours. Every 24 hours the pH, titratable acidity, total solids, fat and protein were analyzed. Sensory acceptability was also evaluated with 75 yogurt frequent consumers, who responded with yes or no to the question ?would you consume this product? At the beginning pH, acidity, total solids, fat and protein were 4.35 and 4.36; 0.76% and 0.75%; 12.71% and 13.23%; 3.2% and 3.3%; 4.4% and 4.5%, for the YM and YB respectively, meeting known standards for cow's milk yogurt: range of acidity 0.5%-1.6%, fat maximum value 15% and protein minimum value 2.7%. The sensory acceptability of the YM and the YB was high, with 88.9% and 94.7%, respectively. During storage under accelerated conditions, pH decreased to 3.88 and 3.92; titrable acidity increased to 1.1% and 0.93%; total solids, fat and protein decreased to 9.37% and 9.7%; 2.4% and 2.0%; 2.5% and 2.6%, for the YM and YB respectively, while remaining within the limits of the standards consulted. The sensory acceptability decreased to 4% and 5.33% for YM and YB respectively. Therefore the shelf life of the sensory acceptability was estimated (S.S.A) at 4°C in a rejection percentage of 25% and 50%, 69 and 49 h; 193 and 111 h, for the YM and YB respectively.

Comparative rheological study of goat milk yoghurt and cow milk yoghurt

Goat is popularly known as poor man’s cow (or mini-cow) because of its immense contribution to the poor man’s economy. Like milk, yoghurt is also very nutritious. It has been demonstrated that acid milk is better to digest than normal milk.The most important benefits of yoghurt consumption cover the reduction of blood cholesterol level, anti-cancer effects and the improvement of antimicrobial activity and immunity in the human body.From the point of view of rheology, yoghurt is a non-Newtonian, rheological unstable, viscoelastic and pseudoplastic fluid.Beside the sensory quality, another important factor for the consumer's acceptance of the product are the rheological properties of yoghurt, such as apparent viscosity and flow behaviour.An important role is also played by the composition and physicochemical properties of milk which yoghurt is prepared from. Because of the differences in composition and physicochemical properties of goat and cow milk differences in the rheological properties of yoghurt from these types of milk can be expected.Texture analysis of goat and cow milk yoghurt was carried out to compare the quality of yoghurt using instrument namely TA.XT Plus texture analyzer. Study revealed that goat milk yoghurt was having lower firmness, consistency, cohesiveness and index of viscosity than cow milk yoghurt

Cupuassu (Theobroma grandiflorum) pulp, probiotic, and prebiotic: Influence on color, apparent viscosity, and texture of goat milk yogurts

Cupuassu is an acidic fruit that has a characteristic aroma, flavor, and texture; its fiber-rich pulp can provide a different consistency than other fruit pulps. Goat milk is an excellent source of amino acids, fatty acids, and minerals, and is widely used for processing fermented milks, such as yogurt. However, compared with cow milk yogurts, it is difficult to make goat milk yogurts with a good consistency. Therefore, it is necessary to use certain technological strategies. This study was carried out to investigate the possibility of adding cupuassu pulp, probiotic (Lactobacillus acidophilus LA-5), and prebiotic (inulin) to improve the texture of goat milk yogurt. A total of 6 treatments were performed: natural (N), probiotic (Pro), prebiotic (Pre), synbiotic (S), cupuassu (C), and probiotic with cupuassu (PC). The viability of probiotic in yogurts (Pro, S, and PC) was evaluated. In addition, instrumental analyses (pH, color, apparent viscosity, and texture) were performed to evaluate the influence of these different ingredients on goat milk yogurts. The probiotic bacteria remained viable (≥7 log cfu·mL−1) throughout the 28d of refrigerated storage, which exceeded the minimum count required to confer probiotic physiological benefits. The pH levels of the yogurts inoculated with L. acidophilus (Pro, S, and PC) were lower than others yogurts (N, Pre, and C). However, all yogurt samples underwent gradual decreases in pH until 7 to 14d of storage. The lightness (L*) was affected initially by addition of all ingredients (cupuassu pulp, probiotic, and prebiotic). The addition of cupuassu pulp (C and PC) increased the L* during the period of storage. Apparent viscosity and firmness decreased in the PC yogurt. The consistency was highest in the yogurts with added prebiotic (Pre and S) than the other yogurts (N, Pro, C, and PC) at the end of the storage period (d 28). The cohesiveness remained constant in all yogurts (N, Pro, Pre, S, C, and PC). Based on the results obtained from the current study, it was concluded that cupuassu pulp addition improves the texture of goat milk yogurts. Therefore, this pulp could be an important technological strategy for the dairy goat industry.

Preparation of cow milk yoghurt blended with soymilk

Yoghurt was prepared from cow milk blended with soymilk in the Dairy Technology laboratory of Department of Animal Husbandry and Dairy science, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola (M.S.). Yoghurt prepared with different combinations of cow milk and soymilk as 100:00 (T 1 ), 75:25 (T 2 ), 50:50 (T 3 ), 25:75 (T 4 ) and 00:100 (T 5 ) was evaluated for various sensory attributes and the results revealed that overall acceptability scores obtained were 96.03, 91.34, 87.58, 83.33 and 80.33 for the treatment T 1 , T 2 , T 3 , T 4 and T 5 , respectively. Fat, SNF, acidity and TS of yoghurt samples were decreased normally while protein and moisture increased with increase in levels of soymilk. The per kilogram production cost of yoghurt was decreased with increase in soymilk percentage i.e.Rs. 37.63 for (100 % cow milk yoghurt), Rs. 21.38 (50:50 cow milk and soymilk) and Rs. 15.25 for 100 per cent soymilk. It was found that yoghurt prepared from various combinations upto 50 per cent cow milk and 50 per cent soymilk was most acceptable.

Suitability of camel milk for making yogurt

Yogurt was produced using camel milk (CAM). Stabilizers (CMC, pectin, gum acacia, or alginate) were added at 0.6% to improve the texture and acceptability of CAM yogurt. The pH (4.59–4.63) and titratable acidity (0.71–0.87 %) of the CAM yogurt product were different from cow milk control yogurt. CAM yogurt contained 10.6 mg/mL of lactic acid based on HPLC. The separated whey (33.5%) of CAM yogurt with alginate was higher than for control cow milk yogurt (23.8%), indicating a weaker water holding capacity. Stabilizers did not improve the consistency and coagulum of CAM yogurt, compared with bovine milk yogurt.

Test of improvement of the soymilk quality

The milk remains a major food supply to the Man and his demand is ever growing. This important application involves high price of a liter of milk and thus an inability of certain non- producer to meet the needs of their peoples countries. Faced with this situation some countries including Algeria must think of now is to find a way to reduce this dependence by substituting cow's milk, in part, by another abundant commodity in the world and cheaper. In this work we extracted milk by grinding soybeans mixed with water and then brought to boiling and filtered. Similarly, we used the soy flour. Soymilk, we extract and then improved by 20 % of cow milk, is a healthy drink liquid, and organoleptic (flavor, color, appearance, odor) and satisfactory nutritional. Similarly, the yogurt obtained by this mixture has a smooth, creamy texture, smooth and with a significant characteristic white color in mammalian milk. Similarly, the nutritional value is very close to that of cow milk yogurt. This milk is as a very interesting alternative.

Influence of lupin (Lupinus albus L.) yoghurt on mineral content and functional properties of tarhana

Tarhana is a fermented cereal-yoghurt-vegetable based product that contains high amounts of protein, mineral and vitamin. In this research, lupin yoghurt (LY) was produced from fermented lupin milk, and replaced with cow's milk yoghurt up to 100% (w/w) level in tarhana formulation. LY substitution increased protein content of final product from 13.12% up to 14.87%. The redness (a*), yellowness (b*) and hue values of tarhana samples changed significantly (P<0.05) with LY usage. Tarhana samples prepared with 100% LY had the lowest a* and b*, and the highest hue values. Tarhana containing high amounts of LY had rich copper, iron, manganese and zinc contents compared to control tarhana. Especially manganese content of the tarhana increased up to 177 times with LY substitution. While LY over 25% level improved the functional properties such as foaming capacity, water absorption capacity and emulsifying activity of tarhana samples, foaming stability was negatively affected by LY substitution. Colour, taste, consistency, sourness and overall acceptability scores decreased at high substitution levels of LY.

QUALITY AND MICRIOBIOLOGICAL EVALUATION OF AFRICAN YAM BEAN YOGHURT SUPPLEMENTED WITH COW MILK

The utilization of African yam bean for the production of yoghurt substituted with cow milk was studied. African yam bean milk was extracted from dehulled seed, pasteurized and fermented with Yoghurmet® in ratios with reconstituted cow milk powder in the ratios 50:50, 70:30, 90:10, 100:0 and 0:100 (African yam bean milk:Cow milk). Sample 0:100 which was 100% cow milk yoghurt served as the control. The samples were stored for 14 days at 4oC and 3 days at room temperature. The results of the proximate composition of the fresh samples in percentages are; Moisture: 82.76, 81.62, 83.62, 86.53 and 85.42. Total solids: 17.25, 18.47, 16.35, 13.47and14.57. Protein: 5.93, 4.27, 5.87, 5.57 and 5.14. Ash: 0.94, 0.83, 0.91, 0.90 and 0.87. Fat: 1.07, 2.53, 1.18, 1.45 and 1.75. Carbohydrate: 9.09, 10.73, 8.33, 5.53 and 6.78 for the samples 100:0, 0:100, 90:10, 70:30 and 50:50 respectively. The moisture, total solids, fat and carbohydrate contents differed significantly (p≤0.05) in all the samples. The protein content of 100:0 and 90:0 did not differ significantly but differs in other samples. 0:100 differ significantly from other samples in ash content. There was no fiber in the samples. The total viable microbial count was highest in 70:30 (1×107cfu/ml) for refrigerated storage samples while 50:50 (9.5×106cfu/ml) had the highest count in room temperature storage samples. There were no yeasts/moulds enumerated in the refrigerated storage samples while yeast/moulds appeared in 100:0 (3×106cfu/ml) and 70:30 (1×106cfu/ml) on the 3rd day of room temperature storage. The titratable acidity of all the samples increased gradually throughout the storage period while their pH decreased. The specific gravity of the samples also decreased gradually throughout the storage period. The anti-nutritional composition of the samples containing African yam bean was also determined. The sensory properties showed that samples stored at refrigeration temperature maintained good quality up to 14 days of storage and that sample 50:50 was most preferred.

Survival of Bifidobacterium bifidum in cow- and camel-milk yogurts enriched with Cinnamomum verum and Allium sativum

The effects of Allium sativum and Cinnamomum verum water extracts on the survival of Bifidobacterium bifidum during 21days of refrigerated storage and after simulated gastrointestinal digestion (SGD) were investigated. Two types of yogurt (cow- and camel-milk yogurts) were prepared in the presence of A. sativum or C. verum. The viable cell counts (VCC) of B. bifidum in fresh A. sativum- or C. verum-cow milk yogurt (1day) were higher (8.1×109cfu/ml and 6.6×109cfu/ml, respectively; p<0.05) than plain-yogurt (1.9×109cfu/ml). In contrast, B. bifidum VCC in fresh plain-camel milk yogurt was 1.99×109cfu/ml whereas the presence of A. sativum or C. verum in yogurt increased (p<0.05) VCC to 19.61×109cfu/ml and 25.55×109cfu/ml, respectively. The VCC of B. bifidum in both herbal-yogurts decreased (p<0.05) during refrigerated storage for both types of yogurt. The VCC of B. bifidum was ∼1.3×109cfu/ml in all fresh cow milk yogurts after 1h gastric digestion. Intestinal digestion (1h) increased VCC of B. bifidum in all fresh yogurts but not in 7day old yogurts (plain- and A. sativum-yogurts). However, prolonged digestion to another 1h in intestine reduced (p<0.05) VCC of B. bifidum in all fresh and storage yogurts. In contrast, all fresh camel milk yogurts showed VCC of B. bifidum ⩽1×109cfu/ml after SGD. Seven day old A. sativum – camel milk yogurt showed the lowest survival of B. bifidum after gastric digestion compared to plain- and C. verum-yogurt. The VCC reduced (p<0.05) in all camel milk-yogurts after 2h intestinal digestion.

Changes on expected taste perception of probiotic and conventional yogurts made from goat milk after rapidly repeated exposure

Goat milk yogurt is an excellent source of fatty acids, protein, and minerals; however, it is not well accepted by many consumers, due to its typical flavor derived from caprylic, capric, and caproic acids present in this milk and dairy products. Recently, the repeated-exposure test has been used to increase the consumption of particular foods. This methodology has been used to increase children’s willingness to eat food in some settings and has also been used to reduce sodium in soup. Based on these considerations, the aim of this study was to investigate whether repeated exposures may increase acceptance of both goat milk yogurt and probiotic goat milk yogurt. In a pre-exposure session, a total of 45 panelists (28 females and 17 males) from southeastern Brazil, who were not used to consuming dairy goat milk, evaluated the expected taste perception and the perceived liking after tasting 3 yogurt preparations. Then, consumers were randomly divided into 3 groups and participated in rapidly repeated exposure sessions performed within 6 d. Each panelist consumed only the yogurt that he or she would be exposed to. The day after the exposure sessions, all panelists returned to participate in the postexposure session and were asked to evaluate acceptance, familiarity, and the “goaty taste” characteristic of each yogurt. Regarding the expected liking before tasting, results showed higher expectations for cow milk yogurt compared with goat milk yogurt, which proved that consumers were not familiar with the goat milk yogurt. Likewise, only cow milk yogurt presented high acceptance and familiarity rates, confirming that these panelists were used to consuming cow milk products. With respect to the rapidly repeated exposure, 6 d were enough to significantly increase the consumers’ familiarity with goat milk yogurt and probiotic goat milk yogurt. However, this method was not suitable to significantly increase the acceptance of such products. Nonetheless, a correlation existed between the exposure sessions and the increase in acceptance of the exposure groups. Thus, hypothetically, the increasing of exposure sessions could be a strategy to increase goat milk product acceptance.

Evaluation of 20 Macro and Trace Mineral Concentrations in Commercial Goat Milk Yogurt and Its Cow Milk Counterpart

Concentrations of 20 different minerals in commercial goat milk yogurt (CGY) and its cow milk yogurt (CCY) counterpart were evaluated in reference to goat milk yogurt manufactured from Fort Valley State University (FVGY), Fort Valley, GA, USA. Three different lots of CGY and CCY each were purchased from local retail stores at Warner Robins, GA, and 3 batches of FVGY were made using goat milk from the University milking herd. All 3 types of experimental yogurts were stored at 4&#176C refrigerator for 4 weeks. Twenty major and trace minerals were analyzed by an Inductively Coupled Plasma Optical Emissions Spectrometer (Thermo Jarrel Ash Enviro 36, Worchester, MA), using argon as the carrier gas and the EPA method 6010. Total solids (TS) content (%) of FVGY, CGY and CCY products were 11.03, 13.1 and 11.3, respectively, indicating CGY had higher TS than the CCY and FVGY yogurt. Respective mean mineral concentrations (ppm, wet basis) of FVGY, CGY and CCY were: Ca 1057, 1162, 1160; P 838, 974, 929; K 1327, 1717, 1208; Mg 102, 133, 113; Na 545, 449, 475; Fe 4.28, 3.33, 2.11; Mn 0.24, 0.19, 0.13; Cu 10.5, 9.85, 7.22; Zn 17.5, 11.7, 11.8. Levels of all macro minerals except potassium were higher in commercial goat and cow yogurts than FVGY, which may be due to the higher TS contents. FVGY had higher Fe, Mn, Cu and Zn than both commercial products. The heavy metal (Pb, Cd and Ni) contents (ppm) appeared to be normal range, while Al contents of FVGY, CGY and CCY were 11.9, 8.66 and 7.65, respectively, which were higher than those of Pb, Cd and Ni. Both commercial products contained higher major mineral contents than the university yogurt, which might be attributable to the differences in diet, breed, and stage of lactation of milking animals, as well as the tapioca additive used in the commercial products.

Effect of Lactobacillus LB Fortified Cow Milk Yogurt on Constipation in Children with Cerebral Palsy

Effect of Lactobacillus LB Fortified Cow Milk Yogurt on Constipation in Children with Cerebral Palsy

Kefir에서 분리한 Streptococcus thermophilus LFG를 이용한 우유 및 산양유 요구르트의 품질 특성

This study was carried out to investigate the characteristics of goat and cow milk yogurts containing high-exopolysaccharide fermented by Streptoccous thermophilus LFG isolated from kefir. The pH of cow milk yogurt was higher than that of goat milk yogurt. The contents of lactic acid was greater in goat milk yogurt (743.9-1043.8 mg/100 g) than in cow milk yogurt (441.6-709.9 mg/100 g). The numbers of survival lactic acid bacteria were the greatest in goat milk yogurt fermented by Str. thermophilus LFG. Viscosity was greater in cow and goat milk yogurts cultured by Str. thermophilus LFG than in yogurts by Str. thermophilus TH3. Syneresis of yogurt fermented by Str. thermophilus LFG was 9.6-16.1% and 28.2-31.8% in yogurt fermented by Str. thermophilus TH3 after 10 d storage at 4 o C. Flavor compounds identified from goat milk were acetone, ethylbutanoate, ethyl-3-methylbutyrate, ethyl-2-butenoate and ethylhexanoate, and those from cow milk were ethylbutanoate, acetone, 2-heptanone and acetoin. Flavor compounds detected from goat milk and cow milk yogurts were acetic acid, butanoic acid, butanol, diethylcarbinol, acetone, diacetyl, decane, 2-methyl-3-pentanone, hexanal, 2-heptanone, acetoin, benzaldehyde, dimethyldisulfide, and dimethyltrisulfide. In sensory evaluation, overall preference and texture values were higher in goat milk yogurt fermented by Str. thermophilus LFG than in cow milk yogurts and the yogurt fermented by mixed culture resulted in the highest score.

The Influence of &lt;i&gt;Allium sativum &lt;/i&gt;or &lt;i&gt;Cinnamomum verum&lt;/i&gt; on Cow- and Camel-Milk Yogurts: Proteolytic and Angiotensin-I Converting Enzyme-Inhibitory Activities

Yogurt is a nutritious dairy product, has established probiotics effects and may even be therapeutic for certain health conditions. Proteolytic activity of starter cultures during milk fermentation can be generating peptides with angiotensin-I converting enzyme (ACE-I; EC. 3.4.15.1) inhibitory activity. Effects of presence ofAllium sativumorCinnamomum verumon these peptides in yogurt were investigated. Two types of milk (cow and camel) were incubated (41°C) with starter culture in the presence ofA. sativumorC. verumwater extract until pH of yogurt was reduced to 4.5. The resulting herbal-yogurts were evaluated with respect to changes ofin vitroACE-I inhibitory activity and proteolytic activity during 21 days of storage. In the present study, the extent of proteolysis was higher (p&lt;0.05) in presence ofA. sativumthan presence ofC. verumduring storage with cow milk yogurt being more susceptible than camel-milk yogurt. The presence ofA. sativumorC. verumincreased ACE-I inhibitory activity more in cow-than camel-milk yogurt during storage. All herbal-yogurts showed the highest inhibitory activity of ACE-I (40%- 70%) on day 7 of storage. Prolonged storage of both types of yogurt to more two weeks decreased ACE-I inhibition activity (37% - 50%; p&lt;0.05). In conclusion,A. sativumandC. verumcan enhance yogurt functional properties with potential therapeutic values for hypertension.

Antioxidant activity and viability of lactic acid bacteria in soybean-yogurt made from cow and camel milk

In the present study soybean (Glycine max L.) was included in cow and camel milk during fermentation. The resulting soybean-yogurt was evaluated with respect to the changes of post-acidification, viable cell counts (VCC) of Lactobacillus spp. and Streptococcus thermophilus, total phenolic content (TPC) and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) inhibition assay during 21 days of refrigerated storage. The presence of soybean in fresh cow- and camel-milk yogurts did not affect pH reduction compared to respective plain-yogurt. However, soybean–camel milk yogurt showed significant reduction in pH (4.05±0.06) compared to plain-yogurt 4.35±0.02 on day 7 of storage. Titratable acidity (TA) increased in soybean–cow milk yogurt (p<0.05) but not in soybean–camel milk yogurt as compared with respective plain-yogurt during period of storage. The presence of soybean in fresh yogurt showed increased (p<0.05) in Lactobacillus spp. VCC by 10% in cow milk-yogurt and 30% in camel milk-yogurt compared to respective plain-yogurts. On the other hand, VCC of S. thermophilus was higher (p<0.05) in the presence of soybean in cow milk yogurt than in camel milk yogurt. Soybean–camel milk yogurt had 2-folds higher TPC on day 0 and 7 (149.59±1.8 and 111.44±2.8μgGAE/ml respectively) than plain-camel milk yogurt (60.04±0.01 and 55.22±0.01μgGAE/ml respectively). The highest value of TPC in soybean–cow milk-yogurt was showed on day 21 of storage (43.17±1.2μgGAE/ml). The antioxidant activity increased (p<0.05) in the presence of soybean in both cow and camel milk yogurts compared to respective controls. The highest antioxidant activity was shown on day 0 for soybean–cow milk yogurt (61.76±2.2%) and day 7 for soybean–camel milk yogurt (53.16±0.1%). In conclusion, the addition of soybean in both cow- and camel-milk yogurts enhanced the viability of LAB and antioxidant activity during refrigerated storage.

Change of fatty acid profile, including conjugated linoleic acid (CLA) content, during refrigerated storage of yogurt made of cow and sheep milk

Changes in conjugated linoleic acid (CLA) concentration, fatty acid profile and chemical composition of yogurts from cow and sheep milk, produced with traditional methods, were determined during a 14-day storage at 5°C. When fatty acid (FA) composition of yogurts was expressed as g/100g of edible portion (EP) saturated fatty acids (SFAs) significantly increased (P<0.05) during storage while monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) showed the opposite tendency in cow milk yogurts. No significant change was observed in SFAs, MUFAs and PUFAs in sheep milk yogurts. When FA composition of yogurts was expressed in g/100g dry matter (DM), SFAs showed a significant decrease during storage (P<0.05). The c-9, t-11 CLA isomer ranged between 0.24 and 0.45g/100g fat in cow milk yogurts, while in sheep milk yogurts between 0.47 and 0.76g/100g fat. During the 14-day storage at 5°C, CLA significantly decreased (P<0.05) at the end of the storage time in cow milk yogurts, while in sheep milk yogurts it significantly increased (P<0.05). n-3 fatty acids showed a significant increase at the end of the storage period (P<0.05) and this increase was more evident in sheep milk yogurts.

Quality characteristics and antioxidant activity of hickory-black soybean yogurt

Hickory-black soybean milk and reconstituted milk (about 12 g/100 g solid content) were mixed in the proportion of 2:3 by volume to prepare hickory-black soybean yogurt (HBY). Cow milk yogurt (CMY) with no addition of hickory-black soybean milk was used as the control. Compared with CMY, HBY had higher water holding capacity, fat, crude protein and amino acids, but lower susceptibility to syneresis and ash content, and had no significant difference in the total count of lactic acid bacteria (p > 0.05). Sensory evaluation showed that the appearance and flavor scores of HBY had no significant difference from CMY (p > 0.05), but the texture score was significantly higher (p < 0.05). IC50 values of DPPH, OH scavenging ability, Fe2+ chelating ability and inhibition of lipid peroxidation of HBY were lower (p < 0.05) than those of CMY. These results suggested that the antioxidant activity of HBY was significantly higher than that of CMY.

Chemical characteristics, fatty acid composition and conjugated linoleic acid (CLA) content of traditional Greek yogurts

Many studies with conjugated linoleic acid (CLA) indicate that it has a protective effect against mammary cancer. Because dairy products are the most important dietary sources of CLA, we have investigated the CLA concentrations and additionally the fatty acid profiles and chemical composition of several commercial, traditional, Greek yogurts from different geographical origin. The fat content of yogurts was in the order of goat<cow<sheep. Cow, sheep and goat milk yogurts contain respectively 0.128-1.501, 0.405-1.250 and 0.433-0.976 g CLA/100 g fat. Low-fat milk yogurts showed lower values of c-9, t-11 CLA content on lipid basis compared to full-fat yogurts. Samples from mountain areas showed average c-9, t-11 CLA content higher than those from prairie districts. The highest amounts of saturated fatty acids (SFA) were found in low-fat yogurts, of monounsaturated fatty acids (MUFA) in sheep milk yogurts and of polyunsaturated fatty acid (PUFA) in low-fat cow milk yogurts.

Viability of lactic acid bacteria and sensory evaluation in Cinnamomum verum and Allium sativum-bio-yogurts made from camel and cow milk

The present study investigate the effect of herbal water extract prepared from Allium sativum and Cinnamomum verum on the viability of lactic acid bacteria (Lactobacillus spp and Streptococcus thermophilus) in cow- and camel-milk yogurts during 21 day refrigerated storage. The organoleptic properties of fresh-yogurts were evaluated. Lactobacillus spp count for fresh cow milk-yogurts (0 day) in both present and absent of C. verum and A. sativum was ranged from 1.4×06 to 2.1×106 cfu/mL. These values were not significantly changed throughout the 21 days of refrigerated storage. Lactobacillusspp count in fresh plain camel milk- yogurt was 13.2×106 cfu/mL whereas fresh C. verum- and A. sativum-camel milk- yogurts had higher Lactobacillusspp counts (19.2×106 and 26.9×106 cfu/mL respectively; p<0.05). However, refrigerated storage to 21 days resulted in linear decrease in Lactobacillusspp counts. Furthermore, S. thermophilus counts in fresh cow- and camel- milk yogurts in either absent or present of C. verum or A. sativum ranged from 2.4 to 3.6×108cfu/mL and these values increased by day 14 of storage. In organoleptic properties of yogurts no differences were observed in sourness, bitterness, and overall preference scores between the two groups of yogurts. The present of A. sativum in cow milk-yogurt reduced the aroma score to (2.3±0.7, p<0.05) compared to camel milk-yogurt (5.5±1.0).

Comparative antioxidant activity, proteolysis and in vitro α-amylase and α-glucosidase inhibition of Allium sativum-yogurts made from cow and camel milk

The presence of extract of plant with medicinal properties during milk fermentation could enhance the therapeutical values of yogurt. In the present study, the effects of Allium sativum on the changes in post-acidification, total phenolic content (TPC), proteolysis by o-phthaldialdehyde (OPA) assay, antioxidant activity by (1,1-diphenyl-2-picrylhydrazyl radical (DPPH) inhibition) and capacity to inhibit in vitro α-amylase and α-glucosidase activities in cow or camel milk yogurt (MY) during 21day refrigerated storage were investigated. The presence of A. sativum enhanced more pH reduction for camel-MY than for cow-MY compared to their respective controls during storage. The reverse was true for total titratable acid. TPC in camel-MY was higher (p<0.05) than that in cow-MY. The presence of A. sativum in cow- and camel-MYs elevated (p<0.05) the TPC, but these changed little during storage. Antioxidant activities (18–38% DPPH inhibition) were not different in both types of yogurts, either in the absence or in the presence of A. sativum. However, camel-MY had an increase (p<0.05) in antioxidant activities (49–65%) during 7–21days of storage. OPA values on day 0 was higher for camel-MY (368.2±14.8mg/g) than for cow-MY (80.1±3.2mg/g). The presence of A. sativum increased OPA values more for cow-MY than for camel-MY (3.0- and 1.3-folds, respectively). Higher inhibition (p<0.05) of α-amylase by camel-MY compared to cow-MY occurred whereas α-glucosidase inhibition by cow-MY reduced (p<0.05) as a result of refrigeration greater than 7days. In general, the addition of A. sativum caused more antioxidant activities, proteolysis and enzymes (α-amylase and α-glucosidase) inhibition in camel-MY than in cow-MY.