The impact of dietary supplementation with guava (Psidium guajava L.) agroindustrial waste on growth performance and meat quality of lambs.

The aim of this study was to evaluate the growth performance and meat quality of lambs (40 animals) fed with increasing levels (0; 7.5; 15.0; 22.5 and 30.0%) of guava agroindustrial waste (GAW). The pH, cooking loss, colour and chemical composition were measured in the Longissimus lumborum (LL) muscle. A sensory analysis was performed with a panel of eight trained testers using a quantitative descriptive method in order to define sensory descriptors and their intensities. The lambs obtained a mean weight gain of 316 g/day consuming 1.32 kg/day of dry matter. The inclusion of GAW in the diet of lambs did not affect pH, L*, a* and b*. However, significant difference (P < .05) among the treatments were obtained for the chemical composition of LL: moisture decreased, while ash increased and intramuscular fat increased until 15% and then decreased at 22.5% with the inclusion of GAW. However, the sensorial characteristics of lamb meat (lamb odour and flavour, tenderness and juiciness) were not affect by the inclusion of GAW. Therefore, GAW can be included up to 30% in lamb feed without compromising the performance, physic-chemical and sensory characteristics of meat.

Developing cookies formulated with goat cream enriched with conjugated linoleic acid.

Goat fat is one of the best sources of conjugated linoleic acid (CLA), a fatty acid which has health benefits. However, though CLA is generated in ruminants, CLA consumption is limited to meats and milk products. This study aimed to replace vegetable fat with goat milk fat enriched with CLA. From differing fat sources, four cookie recipes were developed: CVF-vegetable fat cookies; CB-butter cookies; CG-goat milk fat cookies without CLA; CGCLA-goat milk fat cookies with CLA. The cookies were evaluated using physical (color and texture), physical-chemical parameters (lipids, proteins, total sugars, fiber, ash, moisture and Aw), consumer testing (n = 123), and lipid profiles. The CGCLA presented higher values in the color parameters. The highest and the lowest scores obtained for hardness were respectively 5.54 (CB) and 2.21 (CVF). Lipids and total sugars varied inversely; the highest percentages of lipids were in the CVF and CG samples which obtained lower total sugar content. There were no differences in acceptance or preference for the four formulations. The goat cream formulations (CG and CGCLA) were as well accepted as the CFV formulation. For lipid profiles, CFV presented the highest percentage of trans-fatty acids (TFA) at 16.76%. CGCLA presented 70% more CLA than either CB or CG, certifying that CGCLA presents CLA in relevant quantities, even after cooking. The CGCLA presented higher levels of CLA, and in this study it was verified that goat milk cream enriched with CLA can be used in producing cookies, adding functional and nutritional properties, and offering another alternative(s) to produce food from goat milk fat.

Composition and isolation of goat cheese whey oligosaccharides by membrane technology.

The present research aimed investigates the characterization and concentration of oligosaccharides naturally present in goat cheese whey obtained from two types of goat milk. The goat cheese whey was processed by a two-step cross-flow filtration process and a hydrophilic interaction chromatography - Ultra-Performance Liquid Chromatography coupled to a High Definition Mass Spectrometry. A Quadrupole Time-of-Flight (HILIC UPLC-HDMS-Q-TOF) method was used to identify and measure five different oligosaccharides in the samples. A final product with recovery of 63-96% of oligosaccharides was obtained when compared with the original whey. These components indicate that goat whey can be used as a source of oligosaccharides with potential functional and possible application for human nutrition.

Proteomic of goat milk whey and its bacteriostatic and antitumour potential.

Goat whey is normally discarded in the milk processing industry. However, several studies have addressed its biological properties and possible use in human or animal diet. The present study aimed to analysis the protein profile of goat whey to evaluate its possible oxidant, antioxidant, antibacterial, antitumour, and cytotoxic activities in vitro against human erythrocytes. Goat whey was skimmed, and crude protein extract (CPE) was obtained. Next, protein fractions (F) were obtained using ammonium sulphate precipitation method. The proteins were characterized by SDS-PAGE, two-dimensional electrophoresis and soluble protein measurements. No significant differences were observed in protein profile of CPE, F 30-60% and F 60-90%. The highest protein content was found in F 60-90% (0.41mgP/mL). All samples, except F 0-30% showed bacteriostatic activity against different bacterial strains. Only CPE at a concentration of 1000µg/mL was haemolytic against human erythrocytes. Oxidant activity against erythrocytes was not observed. Antioxidant activity was observed only for CPE. Cytotoxicity against C6 rat glioma cell line that was performed with CPE revealed tumour cell death>70% at concentrations of 0.05 and 0.1µg/mL. These results demonstrate at first time that CPE may be used as an antioxidant, bacteriostatic and cytotoxic compound against tumour cells.

New insights on the metabolism of ricinoleic acid in ruminants.

Dairy goats were fed a total mixed ration with or without the inclusion of castor oil [40 g/kg of dry matter (DM)] to study the metabolism of ricinoleic acid (12-OH,cis-9-18:1). Ten goats, at 39.7 ± 4.0 d in milk, were individually penned and allocated at random to the 2 experimental diets. Goats were manually milked twice a day. Milk fatty acids (FA) were analyzed as methyl esters and hydroxyl groups were derivatized in trimethylsilyl ethers. Apart from ricinoleic acid, 6 FA were only detected in the milk of the castor oil group. Ricinoleic acid composed 0.3% of total FA in milk of the castor oil group, whereas the hydroxy-FA (8-OH-14:0, 10-OH-16:0, and 12-OH-18:0) and oxo-FA (8-oxo-14:0, 10-oxo-16:0, and 12-oxo-18:0) reached 7.5% of total FA in milk. We anticipate that these FA were derived from the metabolism of ricinoleic acid, although it was not clear if they were produced in the rumen or in the tissues. To confirm that, we conducted in vitro batch incubations repeated for 3 consecutive weeks with castor oil (40 g/kg of DM) and strained rumen fluid from 2 fistulated sheep. To examine the products formed over time, incubation tubes were stopped at 0, 6, 12, 24, 48, and 72 h. The results of the in vitro experiment showed that ricinoleic acid was metabolized in the rumen at a slow rate and the main products formed were 12-OH-18:0 and 12-oxo-18:0, by hydrogenation of the cis-9 double bond, followed by oxidation of the hydroxyl group, respectively. Our results suggest that the 12-OH-18:0 and 12-oxo-18:0 escape rumen and are further metabolized through partial ß-oxidation in ruminant tissues. We propose that the 10-OH-16:0 and 8-OH-14:0 found in goat milk of the castor oil group are successive products of the ß-oxidation of 12-OH-18:0, and the 10-oxo-16:0 and 8-oxo-14:0 are successive products of the 12-oxo-18:0 in tissues. Overall, our results indicate that ricinoleic acid is extensively metabolized in the rumen and tissues, producing mainly oxo- and hydroxy-FA that are further excreted in milk.

Influence of the addition of Lactobacillus acidophilus La-05, Bifidobacterium animalis subsp. lactis Bb-12 and inulin on the technological, physicochemical, microbiological and sensory features of creamy goat cheese.

The effects of the addition of Lactobacillus acidophilus LA-05, Bifidobacterium animalis subsp. lactis BB-12 and inulin on the quality characteristics of creamy goat cheese during refrigerated storage were evaluated. The manufactured cheeses included the addition of starter culture (Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris - R-704) (CC); starter culture, L. acidophilus LA-05 and inulin (CLA); starter culture, B. lactis BB-12 and inulin (CBB); or starter culture, L. acidophilus LA-05, B. lactis BB-12 and inulin (CLB). In the synbiotic cheeses (CLA, CBB and CLB), the counts of L. acidophilus LA-05 and B. lactis BB-12 were greater than 6log CFU g-1, the amount of inulin was greater than 6 g per 100 g, and the firmness was reduced. The cheeses evaluated had high brightness values (L*), with a predominance of yellow (b*). CC had higher contents of proteins, lipids and minerals compared to the other cheeses. There was a decrease in the amount of short-chain fatty acids (SCFAs) and an increase of medium-chain (MCFAs) and long-chain fatty acids (LCFAs) in the synbiotic cheeses compared to CC. The amount of conjugated linoleic acid increased in CLA, CBB and CLB. The highest depth of proteolysis and the greatest changes in the release of free amino acids were found in CLB. The addition of inulin and probiotics, alone or in co-culture, did not affect the cheese acceptance. Inulin and probiotics can be used together for the production of creamy goat cheese without negatively affecting the general quality characteristics of the product, and to add value because of its synbiotic potential.

Anxiety behavior is reduced, and physical growth is improved in the progeny of rat dams that consumed lipids from goat milk: an elevated plus maze analysis.

The goat milk contains conjugated linoleic acid (CLA), which can influence physical growth and brain development. This study investigated the impact of a diet containing goat milk fat (GMF) on physical parameters of gestating (G) and/or lactating (L) rat dams, and their progeny's physical growth, and anxiety behavior. In the dams, body weight was evaluated during gestation and lactation. Maternal physical parameters, thoracic and abdominal circumference and liver weight were measured at weaning. In the progeny, indicators of somatic development, and consolidation of reflex responses (palm grasp, righting, free-fall righting, vibrissa placing, auditory startle response, negative geotaxis and cliff avoidance) were determined. Anxiety behavior was tested on the elevated plus maze (EPM). Compared to the controls, GMF-pups presented higher body weight and tail length at days 18 and 21 (groups G+L and L). In the L-group, cliff avoidance and free-fall righting responses were respectively delayed, and accelerated. Fur appearance was anticipated in G+L pups. On postnatal day 35, the EPM responses of the G group indicated less anxiety than in the controls. Data show developmental and behavioral modifications in the progeny of dams fed the GMF-rich diet consumed during gestation and lactation, suggesting the involvement of CLA in such effects.

Enterotoxin-encoding genes in Staphylococcus spp. from bulk goat milk.

Although Staphylococcus aureus has been implicated as the main Staphylococcus species causing human food poisoning, recent studies have shown that coagulase-negative Staphylococcus could also harbor enterotoxin-encoding genes. Such organisms are often present in goat milk and are the most important mastitis-causing agents. Therefore, this study aimed to investigate the occurrence of enterotoxin-encoding genes among coagulase-positive (CoPS) and coagulase-negative (CoNS) staphylococci isolated from raw goat milk produced in the semi-arid region of Paraiba, the most important region for goat milk production in Brazil. Enterotoxin-encoding genes were screened in 74 staphylococci isolates (30 CoPS and 44 CoNS) by polymerase chain reaction targeting the genes sea, seb, sec, sed, see, seg, seh, and sei. Enterotoxin-encoding genes were found in nine (12.2%) isolates, and four different genes (sea, sec, seg, and sei) were identified amongst the isolates. The most frequent genes were seg and sei, which were often found simultaneously in 44.5% of the isolates. The gene sec was the most frequent among the classical genes, and sea was found only in one isolate. All CoPS isolates (n=7) harboring enterotoxigenic genes were identified as S. aureus. The two coagulase-negative isolates were S. haemolyticus and S. hominis subsp. hominis and they harbored sei and sec genes, respectively. A higher frequency of enterotoxin-encoding genes was observed amongst CoPS (23.3%) than CoNS (4.5%) isolates (p<0.05), reinforcing the importance of S. aureus as a potential foodborne agent. However, the potential risk posed by CoNS in goat milk should not be ignored because it has a higher occurrence in goat milk and enterotoxin-encoding genes were detected in some isolates.

Conjugated linoleic acid in the maternal diet differentially enhances growth and cortical spreading depression in the rat progeny.

BACKGROUND: Conjugated linoleic acids (CLA) are fatty acids that are found in the lipids from goat milk, and appear to protect neurons from excitotoxicity. METHODS: We investigated in developing rats the effects of a maternal CLA-rich diet (containing 7% lipids from goat milk) on body development and cerebral electrical activity of the progeny from dams receiving the CLA diet during gestation (G), lactation (L) or both periods (G+L). RESULTS: Compared to a control group (C) receiving a diet with 7% soybean oil, body weight increased at 14, 21 and 28 days, but not at 35-45 days, in L and G+L groups (P<0.05). No intergroup difference was found on body and brain weights, body length, abdominal and thoracic circumferences, body mass index and abdominal to thoracic circumference ratio at 35-45 days. In contrast, at this later age the CSD velocities of propagation were significantly higher (P<0.05) in L as compared with the C and G group, and in the L+G, as compared with the C, G and L groups, suggesting a long-lasting brain effect. CONCLUSION: These data indicate that a maternal CLA-rich diet can differentially influence body weight increment (short-term effect), and CSD propagation (long-term effect) in the progeny, and the lactation is the most critical period for such diet actions. GENERAL SIGNIFICANCE: The facilitating effect of the lipids from goat milk on an excitability-related phenomenon in the brain (CSD) can be of clinical relevance, since CSD has been associated to neurological disturbances like migraine and epilepsy.