Effects of sun and freeze-drying techniques on molecular, fatty acid and therapeutic properties of fermented goat milk product (original) (raw)
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Food Chemistry, 2016
The purpose of this study was to evaluate the effect of solar and freeze drying techniques on the physicochemical, nutritional and biofunctional properties of salted or unsalted Jameed from fermented sheep milk product. The highest yield of Jameed was obtained via the salted-solar drying process. As measured by colorimetry, salted freeze-dried Jameed showed improved consumer characteristics in terms of increased lightness and decreased red and yellow color components. When unsalted Jameed was prepared by solar or freeze drying, additional major peptide bands were detected by SDS-PAGE treatments as compared to the solar or freeze drying of the salted Jameed. Use of salt in the preparation of solar dried Jameed also led to the highest ACE inhibitory activities whereas antioxidant activity was lowest in unsalted solar dried Jameed. The study findings indicate that both greater yield and better overall nutritional and biofunctional properties were associated with solar dried salted Jameed.
Jameed is basically a hard cheese-like product considered a very stable and safe dried fermented milk product. It is usually made from sheep buttermilk. The aim of this study was using goat and cow buttermilk or skim milk in preparing of jameed instead of sheep buttermilk. Five treatments of jameed were made from sheep, goat and cow buttermilk and also from goat and cow skim milk. The obtained results showed that yield, total solids, ash, salt in moisture, total protein and non-protein-nitrogen values of jameed made from sheep buttermilk were higher than that of jameed prepared from goat or cow butter and goat or cow skim milk. Sheep buttermilk jameed contained low acidity values than those in jameed prepared from goat and cow buttermilk. Utilization of goat and cow skim milk in jameed making decreased titratable acidity and water soluble nitrogen and increased pH values. Jameed made from goat skim milk had the highest fat contents. Utilization of goat and cow buttermilk in jameed manufacture increased total viable bacterial count, lactic acid bacteria and proteolytic bacteria. Sheep buttermilk jameed showed the best wetability followed by goat and cow skim milk jameed. Levels of jameed syneresis were higher in goat and cow buttermilk jameed than that of jameed made from sheep buttermilk. All values of the textural properties were higher in sheep buttermilk jameed than those of the other treatments. From scanning electron microscopy, it is observed that the protein structure was completely different among stored jameed samples. Jameed with good properties can be made from goat and cow buttermilk or skim milk.
Aparnathi KD (2017) Comparison of Surti goat milk with cow and buffalo milk for physicochemical characteristics, selected processing-related parameters and activity of selected enzymes, Veterinary World, 10(5): 477-484. Abstract Aim: The study was undertaken to find out the physicochemical characteristics, selected processing-related parameters and activity of selected enzymes in Surti goat milk. Materials and Methods: Milk samples from Surti goats and buffalo milk samples were collected during the period from July 2013 to January 2014 at Reproductive Biology Research Unit, Anand Agricultural University (AAU), Anand. Milk samples from Kankrej cows were collected from Livestock Research Station, AAU, Anand. Samples were analyzed for physicochemical characteristics such as acidity, viscosity, surface tension, specific gravity, refractive index, freezing point, and electrical conductivity. Samples were also analyzed for selected processing-related parameters such as heat coagulation time (HCT), rennet coagulation time (RCT), rate of acid production by starter culture, alcohol stability, and activity of selected enzymes such as alkaline phosphatase activity, catalase activity, proteolytic activity, and lipase activity. Results: Goat milk had the highest acidity, viscosity and surface tension, followed by cow milk and buffalo milk. However, the differences in acidity, specific gravity, surface tension, refractive index, electrical conductivity, HCT and lipase activity of three types of milk studied, viz., goat, cow, and buffalo milk were found statistically non-significant (p<0.05). The buffalo milk had the highest specific gravity, followed by those found in cow and goat milk. The viscosity, freezing point and RCT of goat milk was significantly lower (p>0.05) than that of the buffalo milk. However, the difference in viscosity, freezing point and RCT of goat milk and that of the cow milk was statistically non-significant. The cow milk had the highest refractive index, followed by goat and buffalo milk. The cow milk had the highest proteolytic activity and heat coagulation time (HCT), followed by those found in buffalo and goat milk. The goat milk had the lowest freezing point, lipase activity, and RCT, followed by those found in cow and buffalo milk. The goat milk had the highest electrical conductivity, followed by those found in buffalo and cow milk. The collected goat, cow and buffalo milk samples showed negative stability at 68% (v/v) alcohol concentration. Goat milk showed positive alcohol test at 75% (v/v) alcohol concentration. Acidity was found to increase proportionally with time. After 14 h, it was found that goat milk became thicker, but the curd had a very low consistency. Cow milk had the highest alkaline phosphatase activity and catalase activity followed by those found in goat milk and lowest alkaline phosphatase activity and catalase activity was found in buffalo milk. The alkaline phosphatase activity and proteolytic activity of goat milk was significantly lower (p>0.05) than that of the cow milk. However, the difference in alkaline phosphatase activity and proteolytic activity of goat milk and that of the buffalo milk was statistically non-significant. Alkaline phosphatase activity of buffalo milk was significantly lower (p>0.05) than that of the alkaline phosphatase activity in cow milk. Conclusion: It can be concluded from the study that the goat milk has highest acidity, viscosity, electrical conductivity, and surface tension compared to that of cow and buffalo milk. The goat milk has lowest specific gravity, freezing point, proteolytic activity, lipase activity, RCT and HCT compared to cow and buffalo milk. Goat milk had highest refractive index compared to buffalo milk, whereas lowest refractive index compared to cow milk. Goat milk showed positive alcohol test at 75% (v/v) alcohol concentration. The curd formed from goat milk after 14 h was having very weak consistency. The goat milk has higher alkaline phosphatase activity, catalase activity compared to buffalo milk while it has lower alkaline phosphatase activity, catalase activity compared to cow milk.
EFFECT OF UTILIZATION PARTIAL DRYING BY HOT AIR ON THE CHEMICAL COMPOSITION, RHEOLOGICAL AND MICROBIAL PROPERTIES OF JAMEED, 2017
Eleven treatments of jameed were made from sheep butter milk and from goat and cow skim milk. After shaping the jameed paste into balls, control balls (made from sheep butter milk and from goat and cow skim milk) were sun dried for 15 days whereas other balls of goat and cow skim milk jameed were partially dried using hot air at 45ºC/12h, 60ºC/10h, 75ºC/8h and 90ºC/6h then jameed drying process was completed in sun till moisture content of jameed reached to ~20%. Utilization of partially drying after shaping of jameed paste reduced the time of solar drying period. During storage, acidity ratios of sun dried jameed were higher whereas total solids, fat, total protein, ash, salt, water soluble nitrogen and non-protein-nitrogen contents were lower than those of partial dried treatments. Manufacturing of jameed by traditional method (solar drying) increased the numbers of the total viable bacterial count, lactic acid bacteria and proteolytic bacteria as compared with partially dried jameed. Using of high temperatures in partial draying of jameed increased wettability while decreased syneresis values. Also, jameed samples treated with higher temperature of partial drying had the highest levels hardness, cohesiveness, gumminess and chewiness and the lowest levels of springiness. The micrograph images of partially dried jameed treatments showed that protein matrices characterized by little aggregates, plates structure, more open protein network and high fusion. These properties were more obvious with higher temperature heat treatments and in goat skim milk jameed.
Advances in Biological Sciences Research, 2022
The interaction between raw goat milk, lactic acid bacteria (LAB), and kefir grain resulted in the unique taste and flavor of fermented products. Under optimum temperature, LAB and yeast had the better condition for growth and optimizing metabolic activity. The proportion level of kefir grains should be considered during the incubation period because it could change the logarithmic growth phase of lactic acid bacteria. After the processing, cold storage should be applied to suppress microorganism growth in the post-acidification period. The prolonged post-acidification period potentially affects the quality of Goat milk kefir products. This research aimed to evaluate the effect of a post-acidification period during cold storage based on antioxidant, peptides, and chemical quality of goat milk kefir. The experimental design was a completely randomized design (RCD) with four treatments and three replications. The quality analysis was done in the different post-acidification periods for 1 day, 7 days, 14 days, and 21 days after being stored at 4 o C. Duncan Multiple Range Test (DMRT) was used for further statistical analysis. The results showed that the different postacidification periods had significant effects (p<0.05) on antioxidant activity, peptide, fat, and ethanol content. On Average, antioxidant activity, peptide, fat, and ethanol content in goat-milk kefir were 55.70 ± 2.25 %, 9.32 ± 0.13 mg / ml, 1.86 ± 0.08%, and 1.04 ± 0.04%, respectively. In conclusion, the longer period of post-acidification has a major contribution to the change of goat milk kefir characteristics during cold storage.
Effect of freeze-drying on camel's milk nutritional properties
The purpose of this research was to study the effect of freeze-drying process on camel's milk nutritional characteristics compared with fresh milk. The results showed that the protein, casein, whey proteins, lactose and ash percentage were significantly higher (P< 0.05) in freeze-dried skim milk than fresh milk. The average of mineral contents in reconstituted freeze-dried skim camel's milk was slightly higher than that of fresh camel milk except Ca, K and P contents. On the other hand, freeze-dried skim camel's milk had a slightly higher concentration of water-soluble vitamins except vitamin C. Vitamins B, A, D and E showed relatively stable values after freeze-drying treatment. Freeze-drying process skim camel's milk was characterized by slightly higher contents of all amino acids. Freeze-dried whole milk showed higher contribution of Protein efficiency ratio, Biological value and Net protein utilization than that of fresh whole milk. Freeze-dried process had a little effect on fatty acid profile in camel milk fat. Nutritional properties of lyophilized camel's milk remained basically unchanged compared with fresh milk.
Improvement of Chemical Properties of Jameed by Fortification with Whey Protein
Improvement of Chemical Properties of Jameed by Fortification with Whey Protein, 2017
Background: Jameed is a dried fermented milk food commonly used as a traditional dairy product in several Mediterranean countries including Jordan, Syria, Saudi Arabia, Iraq and Egypt.The aim of this work was to study the effect of blending whey protein paste (a by-product in Ras cheese production) with jameed curd on the chemical composition and microbial properties of the produced jameed.
The Journal of dairy research, 2016
The aim of this study was to identify the differences between the main macro and micronutrients including proteins, fat, minerals and vitamins in cow and goat dehydrated fermented milks. Fermented goat milk had higher protein and lower ash content. All amino acids (except for Ala), were higher in fermented goat milk than in fermented cow milk. Except for the values of C11:0, C13:0, C16:0, C18:0, C20:5, C22:5 and the total quantity of saturated and monounsaturated fatty acids, all the other fatty acid studied were significantly different in both fermented milks. Ca, Mg, Zn, Fe, Cu and Se were higher in fermented goat milk. Fermented goat milk had lower amounts of folic acid, vitamin E and C, and higher values of vitamin A, D3, B6 and B12. The current study demonstrates the better nutritional characteristics of fermented goat milk, suggesting a potential role of this dairy product as a high nutritional value food.
Eleven treatments of jameed were made from sheep butter milk and from goat and cow skim milk. After shaping the jameed paste into balls, control balls (made from sheep butter milk and from goat and cow skim milk) were sun dried for 15 days whereas other balls of goat and cow skim milk jameed were partially dried using hot air at 45ºC/12h, 60ºC/10h, 75ºC/8h and 90ºC/6h then jameed drying process was completed in sun till moisture content of jameed reached to ~20%. Utilization of partially drying after shaping of jameed paste reduced the time of solar drying period. During storage, acidity ratios of sun dried jameed were higher whereas total solids, fat, total protein, ash, salt, water soluble nitrogen and non-protein-nitrogen contents were lower than those of partial dried treatments. Manufacturing of jameed by traditional method (solar drying) increased the numbers of the total viable bacterial count, lactic acid bacteria and proteolytic bacteria as compared with partially dried jameed. Using of high temperatures in partial draying of jameed increased wettability while decreased syneresis values. Also, jameed samples treated with higher temperature of partial drying had the highest levels hardness, cohesiveness, gumminess and chewiness and the lowest levels of springiness. The micrograph images of partially dried jameed treatments showed that protein matrices characterized by little aggregates, plates structure, more open protein network and high fusion. These properties were more obvious with higher temperature heat treatments and in goat skim milk jameed.
2021
Processing kefir into powder form is an effort to extend shelf life, prevent contamination from unwanted bacteria, and facilitate storage. For this reason, a proper drying method is needed to produce a good quality kefir powder. There are three types of drying methods used in this study, namely drying with a cabinet dryer, freeze dryer, and spray dryer. The purpose of this study was to determine the effect of different types of drying methods on pH value, solubility, viscosity, total acid, and alcohol content of goat's milk kefir powder after storage for two months. This study used a completely randomized design method with different types of drying methods, namely T1 (cabinet dryer), T2 (freeze dryer), and T3 (spray dryer). The data were analyzed using Analysis of Variance (ANOVA) with a confidence level of 95% and if it had a significant effect, it was continued with the Duncan Multiple Range Test. The results showed that the different drying methods did not show any significa...