Characteristics Of Goat Milk Research Articles

Interferência do extrato natural de jatobá (Hymenaea martiana Hayne) sobre as características físico-químicas e o rendimento do leite e queijo coalho de cabra

ABSTRACT Several studies have assessed the therapeutic potential of natural products against mastitis, but only a few have evaluated the impacts of this alternative therapy on the main properties of milk and dairy products. In this study, we observed how the treatment of mastitis with ethanolic extract of Jatobá (Hymenaea martiana Hayne) influenced the physicochemical and sensory characteristics of coalho cheese. An ointment containing the ethanolic extract was prepared for intramammary use in six dairy goats. The experiment was conducted in three experimental moments. Milking was performed, manually, and both milk and cheese were subjected to physicochemical and sensory tests. No difference was observed (p>0.05) in the physicochemical aspects of milk between the studied groups. The solids-non-fat showed a statistical difference between experimental moments M1 and M2. The protein means varied from 3.33 to 3.62, and there was a statistical difference between the two moments, while the lactose means varied from 4.79 to 5.38%. The physicochemical aspects of cheese remained similar with both treatments. Except for appearance, the sensory characteristics showed no statistical difference. In conclusion, the use of Jatobá extract ointment did not influence the physicochemical and sensory characteristics of goat milk or cheese.

Effect of storage on physico-chemical, microbiological and sensory characteristics of goat milk fermented by Lactobacillus strains isolated from minas artisanal cheeses

Lactobacillus spp. are lactic acid bacteria which have important implications for the food industry due to their fermentation capacities. The aims of this research were to produce fermented goat milks with Lactobacillus plantarum B7 and Lactobacillus rhamnosus D1, isolated from Brazilian artisanal cheeses, and to evaluate their physico-chemical, microbiological and sensorial qualities during 30 days of storage at 7°C. The goat milks, fermented by B7, D1, co-culture and a Lactobacillus casei Shirota control, possessed acceptable physico-chemical characteristics to meet fermented milk standards established by Brazilian legislation and maintain the viability of Lactobacillus spp. throughout the shelf life of the products. The products were microbiologically safe. D1 fermented goat milk gave higher consumer sensory quality acceptance and purchase intention (p<0.05) than other treatments, thus Lactobacillus rhamnosus D1 is recommended for fermented goat milk production.

Influence of diet on the productivity and characteristics of goat milk

The relationship between the quality of milk of different breeds of goat and their diets was assessed. Anglo-Nubian, German White and Alpine goats were used in the experiment, with 7 goats representing each breed. The influence of two diets viz., a routine diet (hay and concentrates) and a diet improved by introduction of granulated alfalfa hay, cabbage and carrots, as well as mixed feed on productivity and characteristics of goat milk were investigated. Goats were machine milked twice daily and the quantity as well as quality of milk were assessed. Results indicated that the milk yield of the Alpine goats increased 3 times; and that of the German White goats increased more than 2.5 times when fed improved diet. Feeding improved diet resulted in significant increase in fat content of milk irrespective of the goat breed. A significant increase in the protein, lactose, and consequentially the, dry non-fat milk solids was observed in Anglo-Nubian and German White goats when fed the improved diet. However, when compared to German White and Alpine goats, highest fat, protein and lactose contents were recorded in milk of Anglo-Nubian goats both on routine and improved diet. The maximum difference in biochemical parameters of milk upon changing the diet was also found in Anglo-Nubian goats. Further, the freezing point and electrical conductivity of the milk decreased irrespective of the breed when goats were fed improved diet. An inverse relationship was found between the protein content in the goats’ milk and the freezing point: with increase in the protein content, the freezing point was reduced.

Effect of Source of Heat and Storage Period on Physicochemical and Microbiological Characteristics of Goat Milk

This investigation was conducted to evaluate the effect of heat treatment of goat milk with charcoal, gas and microwave on the physicochemical and microbiological characteristics during the storage period. Raw goat milk was heated with char- coal, gas and microwave at 99°C for 12 min followed by storage at 4°C for 10 days. Physicochemical and microbiological characteristics were determined at 1, 3, 7 and 10-day intervals. The results showed a significant effect of source of heat on the physicochemical characteristics under study except fat content and pH. The highest protein (3.62%), lactose (4.97%) and solids-non-fat (SNF) (9.31%) contents were high in milk heated with charcoal, while fat (5.68%) and total solids (TS) (14.26%) contents were high in milk treated with microwave and the acidity (0.19%) was high in milk treated with gas. The total viable bacteria (TVB) and lactic acid bacteria (LAB) were significantly (P<0.001) higher (log 2.31 cfu/ml and log 2.26cfu/ml, respectively) in milk heated with charcoal. The protein, TS, lactose, SNF and acidity increased during the stor- age period, while fat and ash decreased. TVB and LAB increased during the storage period. Bacillus and Staphylococcus genera survived the heat treatment and were isolated in heated milk till day 7 of the storage period, and then Staphylococcus was not detected at day 10.

Characterization of goat milk and potentially symbiotic non-fat yogurt

Combining prebiotics and probiotic microorganisms improve quality in the formulation of foods. In this paper, the characteristics of goat milk and symbiotic yogurt were studied. Raw goat milk was analyzed and the skimming process was optimized. For the formulation of a potentially non-fat symbiotic yogurt made with skimmed goat milk, inulin, gelatin, sugar, and Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus casei subsp. rhamnoshus. Chemical characteristics, acceptability, and viability of lactic acid bacteria and probiotic culture were assessed. The protein and fat content of the raw milk was 2.90 and 3.56 g/100 mL, respectively. The optimum skimming process was obtained at 9,800 rpm and 4 °C for 15 minutes. The product formulated had a protein and fat content of 4.04 to 0.04 g/100 mL, good sensory properties, and acceptability of 95%. The lactic bacteria count was 9 × 10 7 CFU mL –1 , and probiotic culture count was higher than 1 × 10 6 CFU mL –1 , which guarantees their effect and capacity to survive in the digestive tract and spread in the intestine. The yogurt was stable during the 21 days of storage. Therefore, this study shows that goat milk yogurt is an adequate delivery vehicle of the probiotic culture L. casei and inulin.

Parâmetros de qualidade do leite de cabra armazenado sob frio

O leite de cabra é produzido em pequena escala, o que torna necessária sua estocagem, permitida pela legislação brasileira. O presente trabalho teve por objetivo avaliar a ação do resfriamento e congelamento sobre as características físico-químicas e microbiológicas do leite de cabra. Não foi observada variabilidade nos valores médios de acidez, estabilidade ao álcool, densidade, gordura, proteína, sólidos totais e lactose após armazenamento sob frio. Não foi observada instabilidade ao calor em nenhuma das amostras analisadas. Verificou-se tendência à diminuição na contagem de células somáticas (CSS) no leite congelado em relação ao fresco e ao refrigerado. A quantificação (NMP) de coliformes totais e termotolerantes variou de &lt; 3 (ausência de crescimento) à &gt; 1.100 UFC/mL, independentemente do armazenamento. Entretanto, determinou-se contagem de coliformes totais e termotolerantes significativamente maior (p &lt; 0,0001) nas amostras mantidas sob refrigeração. Na prova de lactofermentação, observaram-se coágulos digeridos, floculosos e sulcados sem estabelecer correlação entre estes e a contagem bacteriana. A CCS e a contagem microbiana são critérios adotados no pagamento pela qualidade no leite caprino, e a temperatura de armazenamento pode influir sobre elas.

Composition and Characteristics of Goat Milk: Review 1968−1979

Research in the past decade has extended knowledge of composition of goat milk and of properties of its constituents. Goats of several European breeds produce milk of lower fat content in the tropics than in temperate zones. Fat, protein, and lactose contents of milk of dwarf goats are higher than those of other breeds. Fat globules of goat milk resemble those of cow milk in lipid composition and properties of the globule membrane, but goat milk lacks “agglutinin” which causes fat globules of cow milk to cluster when cooled. Five principal proteins of goat milk, α-lactalbumin, β-lactoglobulin, κ-casein, β-casein, and αs2-casein, closely resemble their homologs in cow milk. Goat milk lacks a homolog of bovine βs1-casein, the most abundant protein in cow milk. Caseinate micelles of goat milk contain more calcium and inorganic phosphorus, are less solvated and less heat stable, and lose β-casein more readily than bovine micelles. Activities of ribonuclease, lipase, and xanthine oxidase are less in goat than in cow milk. Goat milk contains more potassium and chloride but less orotic acid, N-acetyl neuraminic acid, folate, vitamin B6, and vitamin B12 than cow milk. Little work in the past decade has been on nutritive value of goat milk for humans except to describe cases of folate deficiency in infants.