Apoptosis and necrosis of polymorphonuclear leukocytes in goat milk with high and low somatic cell counts

The purpose of the present trial was to compare the percentages of necrotic and apoptotic polymorphonuclear leukocytes (PMNL) in goat milk with low and high somatic cell count (SCC). Twenty eight milk samples were collected from 20 lactating goats, determined to be negative in bacteriological examination, and divided in three groups, according to their SCC: samples with SCC lower than 500 x 10(3) cells/mL; between 500 and 1500 x 10(3) cells/mL; and higher than 1500 x 10(3) cells/m L. SCC was performed in an automatic somatic cell counter. Apoptosis and necrosis were quantified using dual-color flow cytometry with fluorescein labeled annexin-V and propidium iodide (PI). Results of the present study showed a significant positive correlation between the percentage of the viable PMNL and milk SCC(r = 0.495, P=0.008), as well as a significant negative correlation between apoptotic PMNL and milk SCC(r = -0.486, P = 0.009). Results also pointed out lower PMNL viability rates due to higher apoptosis rates in milk samples with SCC lower than 5 x 10(5) cells/mL. (C) 2011 Elsevier B.V. All rights reserved.

Density and rheological parameters of goat milk

The rheological behavior and density of goat milk was studied as a function of solids concentration (10.5 to 50.0%) and temperature (273 to 331 k). Newtonian behavior was observed for values of total solids (TS) between 10.5 and 22.0% and temperatures from 276 to 331 k changing to pseudoplastic behavior without yield stress for TS from 25.0 to 39.4% at the same range of temperature. Goat milk with TS between 44.3 to 50.0% and temperatures of 273 to 296 k showed yield stress in addition to pseudoplastic behavior. At 303 to 331 k the power law model was observed again, without yield stress. The density of goat milk ranged from 991.7 to 1232.4 kg.m-3.

Biotechnological richness of the northeastern semi-arid region: antioxidant activity of casein hydrolysates from Moxotó goat milk (Capra hircus Linnaeus, 1758) obtained by papain action

This study aimed to identify antioxidant peptides from caprine casein hydrolysates by papain application using MALDI-TOF mass spectrometer, and a 2² full factorial design, with 4 axial points, in order to evaluate kinetic parameters (time and pH) effects on the degree of hydrolysis as well as the antioxidant activity of Moxotó goat milk casein peptides. Degree of hydrolysis was determined by total and soluble protein ratio in casein. Antioxidant activity was measured by ABTS method with 2, 2-cation-azinobis (3-ethylbenzothiazoline-6-sulfonic acid). TROLOX was used as standard. Peptide pattern and sequence of antioxidant amino acids were obtained using MALDI-TOF/MS. The highest degree of hydrolysis (28.5%) and antioxidant activity (2329.6 mmol.L TROLOX. mg- 1 peptide) were observed in the permeate. NENLL, NPWDQVK and LLYQEPVLGPV peptides, detected in the permeate, were pointed as the responsible for antioxidant activity, suggesting their potential application as food supplement and pharmaceutical products.

Adhesion and production of degrading enzymes by bacteria isolated from biofilms in raw milk cooling tanks

Biofilms in milk cooling tanks compromise product quality even on farms. Due to the lack of studies of this topic, this study evaluated the microbiological conditions of raw milk cooling tanks on farms and characterized the microorganisms isolated from these tanks. Samples were wiped off with sterile swabs from seven milk cooling tanks in three different points in each tank. Mesophiles and psychrotrophic counts were performed in all samples. The isolation of Pseudomonas spp., Bacillus cereus and atypical colonies formed on selective media were also performed, totalizing 297 isolates. All isolates were tested for protease and lipase production and biofilm formation. Of the total isolates, 62.9% produced protease, 55.9% produced lipase, and 50.2% produced biofilm. The most widespread genus inside the milk cooling tank was Pseudomonas since it was not possible to associate this contamination with a single sampling point in the equipment. High counts of microorganisms were found in some cooling tanks, indicating poor cleaning of the equipment and providing strong evidences of microbial biofilm presence. Moreover, it is worth mentioning the milk potential contamination with both microbial cells and their degrading enzymes, which compromises milk quality.

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.

Comparison of heat stability of goat milk subjected to ultra-high temperature and in-container sterilisation

Goatmilk with and without stabilizing salt was subjected to in-container and UHTsterilization. Heatstability was assessed by measuring the amount of sediment in the milk. Without stabilizing salts, goatmilk usually produced less sediment when subjected to in-containersterilization compared with UHT processing. Addition of stabilizing salts up to 12.8 mM resulted in a progressive increase in sediment for in-containersterilization. In contrast, adding stabilizing salts at 6.4 mM initially reduced sediment formation in UHT-treated milk but addition of stabilizing salts at 12.8 mM increased sediment formation. Adding stabilizing salts to goatmilk increased pH, decreased ionic calcium, and increased ethanol stability. Adding up to 2 mM calcium chloride increased sediment formation more after UHT treatment than after in-containersterilization. These results suggest that no single mechanism or set of reactions causes milk to produce sediment during heating and that the favored pathway is different for UHT and in-containersterilization processes. Poor heatstability could be induced both by increasing ionic calcium and by decreasing it. Ethanol stability is not a good indicator of heatstability for in-containersterilization, but it may be for UHTsterilization, if milk does not enter the region of poor heatstability found at low concentrations of ionic calcium.

Physical properties of goat milk powder with soy lecithin added before spray drying

P>In this study, physical characteristics of goat milk powder produced with the addition of soy lecithin at levels of 0 (control), 0.4, 0.8 and 1.0 g lecithin/100 g of total solids in concentrated milk before the spray drying process were investigated. Goat milk was pasteurised, concentrated at 40% of total solids, spray dried and packed in plastic bags under vaccum conditions. Lecithin addition decreased the wetting time of milk powders, although no influence was observed on dispersibility, water sorption, water activity and particle size distribution of the powders. Powders with higher levels of lecithin showed significantly lower brightness, with a greater intensity of yellow colour. It was concluded that lecithin addition before spray drying process at the minimal proportion in concentrated milk of 0.4 g lecithin/100 g of total solids in concentrated milk is useful for achieving more rapid wetting time of goat milk powder.

Density and rheological parameters of goat milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Density and rheological parameters of goat milk

The rheological behavior and density of goat milk was studied as a function of solids concentration (10.5 to 50.0%) and temperature (273 to 331 k). Newtonian behavior was observed for values of total solids (TS) between 10.5 and 22.0% and temperatures from 276 to 331 k changing to pseudoplastic behavior without yield stress for TS from 25.0 to 39.4% at the same range of temperature. Goat milk with TS between 44.3 to 50.0% and temperatures of 273 to 296 k showed yield stress in addition to pseudoplastic behavior. At 303 to 331 k the power law model was observed again, without yield stress. The density of goat milk ranged from 991.7 to 1232.4 kg.m-3.

Molecular detection of Brucella melitensis in sheep and goat milk in Iran

Purpose: To detect Brucella melitensis in the milk of reared sheep and goats from Isfahan and Shahrekord regions, Iran. Methods: A total of 225 milk samples (sheep = 125; goat = 100) were collected from Isfahan and Shahrekord regions, Central Iran. Polymerase chain reaction (PCR) was used to detect the presence of B. melitensis in the milk following standard procedures. Results: From 225 milk samples, 20 (8.9 %) were positive for B. melitensis. Out of 125 sheep milk, 12 (9.6 %) had B. melitensis, and of these, 8 (66.6 %) were milk collected from Shahrekord and 4 (33.3 %) from Isfahan region. On the other hand, out of 100 goat milk samples, 18 (18 %) were positive for B. melitensis, out of which 10 (55.5 %) were from Shahrekord and 8 (44.4 %) from Isfahan. Conclusion: The findings show that B. melitensis is present in a significant proportion of caprine and ovine milk in a section of Iran.

Projeto e análise térmica de tanques de resfriamento de leite de cabra in natura para quatro ordenhas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dairy goat health management and milk production on organic and conventional system in Brazil

The aimed of this article is to measure risk factors on health and milk production on organic and conventional dairy goats in Brazil. Two experimental groups (organic and conventional) were evaluated simultaneously. The study design was completely randomized. The organic herd consisted of 25 goats and 15 kids. In the conventional production system, a dairy herd comprising 40 goats and 20 kids participated in the study. Data on milk production and health management were available from January 2007 to December 2009. The abortion rate in the conventional system was 5% (2/40) whereas in organic system no abortion was diagnosed (0/25). The mortality rate at weaning in the conventional system was 5% (2/40) and in the organic system was 8% (2/25). Milk production was lower (2.20 kg/day) in organic than conventional system (2.66 kg/day). Goats and kids in organic farm had a higher FEC (386±104 and 900±204, respectively) (p<0.05) than those in conventional farm (245±132 and 634±212, respectively). In addition, Saanen kids had higher FEC (p<0.001) than goats. Treatment with antiparasitic drugs was higher in conventional system (50%) than organic system (1.3%).

Efeito da adição de Trolox® e catalase ao meio glicina-gema-leite sobre o sêmen caprino refrigerado por 24 ou 48 horas em sistema Equitainer®

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Chromatographic determination of fatty acids profiles in regionally-produced Portuguese goat cheese along curing

The biochemistry of cheese ripening involves mechanisms such as glycolysis, proteolysis and lipolysis. Fatty acids are released by the action of lipases from different sources, milk, rennet, bacteria, moulds included as secondary starters, and other exogenous lipases, during lipolysis [1]. The composition of the lipid fraction contributes positively to the flavour of cheese, for being precursors of more complex aroma compounds responsible for the characteristic “goaty flavour” of goat cheeses [2]. Goat milk is recognized by its easier digestibility, alkalinity, buffering capacity and certain therapeutic values in medicine and human nutrition [3]. A high total content of fatty acids is strongly linked to a rancid and tart off flavour in goat milk and may be considered undesirable in most cheese varieties [4]. In this sense, the purpose of the present study was to examine the composition and changes in fatty acids and saponification value of goat cheese during curing period (2, 7 and 12 months). Goat cheese was made in industrial unit of Cachão - Mirandela (Trás-os- Montes) with raw milk Serrana goats’ race, salt and rennet from animal origin. During the first two months, the samples were stored in a ripening chamber (9.5-11 °C and RH 75-85%). From the second month to one year, the samples were stored in a preservation chamber (10.5-12 °C and RH 75-85%). The fatty acids profile of the inner part of the cheese was analyzed by gas-chromatography coupled to flame ionization detection (GC-FID). The degree of saponification was determined both in the crust and inside the cheese by HCl titration of ethanol KOH solution of the samples. Twenty-six fatty acids (FA) were identified and quantified in the inner part of the cheese (total fat was 45-46 g/100 g during the curing period). Saturated fatty acids (SFA) did not change up to 7 months of curing, increasing only after 12 months, being palmitic (C16:0), stearic (C18:0), myristic (C14:0) and capric (C10:0) acids the most abundant FA in this class. Monounsaturated fatty acids (MUFA) decreased only after 12 months, and oleic acid (C18:1) was the predominant FA. In polyunsaturated fatty acids (PUFA) class, the most abundant were linoleic (C18:2) and linolenic (C18:3) acids, and followed the same tendency of MUFA. This is corroborated by an increase in the degree of saponification, either in the crust as in the inner part of the cheese, after 12 months of curing, probably related with the saturation of the fatty acids [3]. Extra-long curing can be done in cheeses produced with goat milk up to seven months of storage without changing the total fat and individual FA content.

Efeito de medicamentos indicados para a prevenção da mastite bovina no período seco sobre a função fagocítica in vitro de leucócitos do leite de caprinos

O uso de medicamentos antimamíticos específicos para vacas no período seco é indicado para prevenção de infecções na lactação seguinte. Não obstante, a ação das células envolvidas no período de secagem tem fundamental importância para a involução da glândula mamária e seu restabelecimento para a lactação subseqüente. A indisponibilidade de tais medicamentos para uso em cabras tem resultado na extrapolação do uso de produtos recomendados para vacas sem que se considerem as particularidades e diferenças anátomo-fisiológicas entre as espécies bovina e caprina. O presente estudo teve por objetivo avaliar a influência de cinco antimamíticos específicos para vacas secas sobre a função dos fagócitos provenientes de leite caprino. Para tal, fez-se o isolamento de células somáticas de 20 amostras de leite provenientes de 10 cabras lactantes, sem antecedentes de tratamento de mamite nos últimos 30 dias, sob condições higiênico-sanitárias de colheita e com resultados negativos ao cultivo microbiológico do leite. As células aderidas a lamínulas de vidro foram confrontadas com formulações contendo princípios ativos disponíveis no mercado como Gentamicina (M1), Cefalônio Anidro (M2), Ampicilina (M3), Cloxacilina Benzatínica (M4) e Cefapirina Benzatínica (M5). Avaliou-se, por microscopia, a fagocitose de partículas de Zymosan. As médias dos índices de fagocitose das células submetidas ao tratamento com M2 (15,12% ± 16,22), M3 (6,02% ± 7,96), M4 (4,54% ± 5,45) e M5 (2,47% ± 4,64) foram menores (p<0,001) que a média dos índices de fagocitose do grupo controle (40,67% ± 19,68). A média dos índices de fagocitose das células submetidas ao tratamento com M2 foi maior (p<0,05) que as médias dos tratamentos com M3, M4 e M5 enquanto estas foram estatisticamente iguais entre si. As amostras celulares submetidas ao medicamento M1 exibiram adesão insuficiente ou ausente às lamínulas, inviabilizando a avaliação da fagocitose por meio da técnica utilizada. Os resultados obtidos permitem concluir que os medicamentos estudados exerceram influência negativa sobre os fagócitos do leite, porém, esta interferência sobre as funções das células somáticas não pode por si só determinar o insucesso da terapia proposta para o período seco, pois deve ser considerada, outrossim, a eficácia do princípio ativo sobre o patógeno causador do processo infeccioso.