Effect of electrical stunning on meat quality of lamb

The effects of stunning on both initial and up to 2 weeks post mortem storage meat quality of Spanish Manchega breed lamb were studied. Twenty-four lambs were distributed into two groups. The first group (US; n =12) were slaughtered without previous stunning. In the second group (ES; n =12) animals were electrically stunned. Meat quality was assessed by examining pH, colour as L*, a*, b* values, water holding capacity (WHC) and shear force (SF). Stunning did not affect any parameter studied in the first 24 h post mortem. There were increasing differences between groups in pH (P<0.001) from 5 days onwards. In general stunning did not have an effect on WHC, SF and colour parameters. Ageing of meat affected SF in the ES group but not in the US one; however, there were no significant differences between treatments at any of the ageing times.     

Indoor air pollution in a Mexican indigenous community: evaluation of risk reduction program using biomarkers of exposure and effect

Indoor air pollution can be an important risk factor for human health, considering that people spend more than 60% of their time indoors. Fifty percent of the world population and approximately 90% of the rural population in developing countries are using biomass as energy source. Latin America represents 12% of the global consumption of biomass; in Mexico, 27 million people use wood as an energy source. Therefore, in this study we evaluated a 3-stage risk reduction program. The stages were: 1) removal of indoor soot adhered to roofs and internal walls; 2) paving the dirt floors; and 3) introduction of a new wood stove with a metal chimney that expels smoke outdoors. The complete intervention program was applied. In 20 healthy subject residents from an indigenous community in San Luis Potosí, Mexico, we measured blood carboxyhemoglobin (% COHb), DNA damage (comet assay) in nucleated blood cells, and urinary 1-OHP levels before and after the program. Before intervention individuals had a geometric mean COHb level of 4.93% and 53% of the population presented levels above 2.5% considered a safe level. However, in all the studied individuals the levels of COHb were reduced to below 2.5% (mean level 1.0%) one month after the intervention. Moreover, when compared, DNA damage in people exposed before the intervention was higher (5.8+/-1.3 of Tail Moment) than when the program was introduced (2.8+/-0.9 of Tail Moment) (P>0.05) and a same trend was observed with urinary 1-OHP levels; 6.71+/-3.58 micromol/mol creatinine was the concentration before intervention; whereas, 4.80+/-3.29 micromol/mol creatinine was the one after the program. The results suggest that the intervention program offers an acceptable risk reduction to those families that use biomass for food cooking.     

Postprandial Lipemia is Modified by the Presence of the <Emphasis Type="Italic">APOB</Emphasis>-516C/T Polymorphism in a Healthy Caucasian Population

Apolipoprotein (apoB) plays a fundamental role in the transport and metabolism of plasma triacylglycerols (TAGs) and cholesterol. Several apoB polymorphic sites have been studied for their potential use as markers for coronary heart disease in the population. In view of the importance of apoB in postprandial metabolism, our objective was to determine whether the presence of the -516C/T polymorphism in the APOB gene promoter could influence postprandial lipoprotein metabolism in healthy subjects. Forty-seven volunteers who were homozygous for the E3 allele at the APOE gene were selected (30 homozygous for the common genotype (C/C) and 17 heterozygotes for the -516T allele (C/T). They were given a fat-rich meal containing 1 g fat and 7 mg cholesterol per kg body weight and vitamin A 60,000 IU/m² body surface. Fat accounted for 60% of calories, and protein and carbohydrates for 15 and 25% of energy, respectively. Blood samples were taken at time 0, every 1 h until 6 h, and every 2.5 h until 11 h. Total cholesterol and TAGs in plasma, and cholesterol, TAGs and retinyl palmitate in triacylglycerol-rich lipoproteins (large and small triacylglycerol-rich lipoproteins) were determined by ultracentrifugation. Individuals carrying the C/T genotype presented greater postprandial concentrations of TAGs in small triacylglycerol-rich lipoproteins than did carriers of the C/C genotype (P = 0.022). Moreover, C/T individuals presented higher concentrations of plasma TAGs during the postprandial period than did C/C subjects (P = 0.039). No other statistically significant genotype-related differences for other parameters were observed. These results suggest that the presence of the genotype C/T is associated with a higher postprandial response. Thus, the allele variability in the -516C/T polymorphism in the APOB gene promoter may partly explain the interindividual differences in postprandial lipemic response in healthy subjects.     

Biological activity of Stevia rebaudiana Bertoni and their relationship to health

The leaves of Stevia rebaudiana Bertoni has nutrients and phytochemicals, which make it an adequate source for the extraction and production of functional food ingredients. Preclinical and clinical studies suggest therapeutic and pharmacological applications for stevia and their extracts because they are not toxic and exhibit several biological activities. This review presents the biological activity of Stevia rebaudiana Bertoni and their relationship to antidiabetic, anticariogenic, antioxidant, hypotensive, antihypertensive, antimicrobial, anti-inflammatory and antitumor activities. Consumption and adverse effects were also reviewed.     

Casein breakdown during ripening of Idiazabal cheese: influence of starter and rennet type

The objective of this work was to determine the effect of starter and rennet type on casein breakdown during Idiazabal cheese ripening. Four batches of cheeses were manufactured with two rennets, commercial calf rennet and artisanal lamb rennet, and the use of natural flora or a commercial starter. Electrophoretic analysis of cheese samples showed six bands identified as α_s1‐, α_s2 + β‐, α_s1‐I‐, γ₁‐, β‐I‐ and para‐κ‐casein. As expected, the casein breakdown during cheese ripening was considerably affected by rennet type and the use of a commercial starter. The artisanal lamb rennet produced a higher hydrolysis of casein fractions than the commercial calf rennet, probably owing to its high percentage of chymosin (around 78%). The effect of addition of starter on proteolysis was dependent on the casein fractions generated by artisanal lamb rennet or commercial calf rennet. © 2000 Society of Chemical Industry     

Clinical Parameters and Epigenetic Biomarkers of Plaque Vulnerability in Patients with Carotid Stenosis

Atheromatous disease is the first cause of death and dependency in developed countries and carotid artery atherosclerosis is one of the main causes of severe ischaemic strokes. Current management strategies are mainly based on the degree of stenosis and patient selection has limited accuracy. This information could be complemented by the identification of biomarkers of plaque vulnerability, which would permit patients at greater and lesser risk of stroke to be distinguished, thus enabling a better selection of patients for surgical or intensive medical treatment. Although several circulating protein-based biomarkers with significance for both the diagnosis of carotid artery disease and its prognosis have been identified, at present, none have been clinically implemented. This review focuses especially on the most relevant clinical parameters to take into account in routine clinical practice and summarises the most up-to-date data on epigenetic biomarkers of carotid atherosclerosis and plaque vulnerability.     

Ovarian stimulation with FSH reduces phosphorylation of gonadotrope progesterone receptor and LH secretion in the rat

Administration of human FSH (hFSH) to cyclic rats during the dioestrous phase attenuates progesterone receptor (PR)-dependent events of the preovulatory LH surge in pro-oestrus. The increased bioactivity of the putative ovarian gonadotropin surge inhibiting/attenuating factor induced by hFSH treatment is not associated with a decrease in PR protein expression, and the possibility of its association at a PR posttranslational effect has been raised. The present experiments aimed to analyse PR phosphorylation status in the gonadotrope of rats with impaired LH secretion induced by in vivo hFSH injection. Two experimental approaches were used. First, incubated pro-oestrous pituitaries from hFSH-injected cycling and oestrogen-treated ovariectomized (OVX) rats were used to analyze the effect of calyculin, an inhibitor of intracellular phosphatases, on PR-dependent LH release, which was measured in the incubation medium by RIA. Second, pituitaries taken from hFSH-injected intact cycling and OVX rats and later incubated with P or GNRH1 were used to assess the phosphorylation rate of gonadotrope. The latter was analysed in formalin-fixed, paraffin-embedded tissue sections by immunohistochemistry using a MAB that recognizes the phosphorylated (p) form of PR at Ser294. Calyculin reduced the ovary-mediated inhibition of hFSH in GNRH1-stimulated LH secretion. In addition, the immunohistochemical expression of pSer294 PR was significantly reduced after ovarian stimulation with hFSH in pituitaries from pro-oestrous rats incubated with P or GNRH1. Altogether, these results suggested that the ovarian-dependent inhibitory effect of FSH injection on the preovulatory LH secretion in the rat may involve an increase in dephosphorylation of PR.     

Effect of lyophilized water extracts of Melissa officinalis on the stability of algae and linseed oil-in-water emulsion to be used as a functional ingredient in meat products

Previous work pointed out the possibility to enhance the nutritional value of meat products using long chain ω − 3 PUFA enriched emulsions. Oil-in-water emulsions elaborated with a mixture of algae and linseed oils (15:10) in order to be used as functional ingredient were stabilized with BHA (butylhydroxyanisol) or with a lyophilized water extract of Melissa officinalis L. (Lemon balm). The lipid profile of the oil mixture showed a high amount of DHA (31.7%), oleic (25.4%) and α-linolenic acid (12.7%) resulting in a very low ω − 6/ω − 3 ratio (0.12). The lyophilized extract of M. officinalis showed a high antioxidant activity (being 62 ppm of the lyophilized water extract of Melissa equivalent to 200 ppm of BHA, using the DPPH assay as reference), and high total phenolic content. Studying the oxidation process in the emulsions during 15 days at room temperature, it could be concluded that this extract was as efficient as BHA in order to control the thiobarbituric acid reactive substances (TBARS) formation.     

Variations in volatile compounds and flavour in Idiazabal cheese manufactured from ewe's milk in farmhouse and factory

Stage of lactation, use of bulk milk or milk from individual flocks, and cheese‐making in farmhouse or industrial factory are important factors affecting the production and quality of Idiazabal cheese. The volatile composition of cheese samples made from raw ewe's milk in farmhouses or industrial plants at two different times of the year and aged for 90 and 180 days was analysed by dynamic headspace coupled to GC‐MS. Short‐chain fatty acids, primary and secondary alcohols, methyl ketones and ethyl esters were the most abundant compounds in the aroma of Idiazabal cheese samples. Differences in the volatile composition were found between farmhouse and industrial cheeses made at different times of the year and ripened for 90 or 180 days. Likewise, the sensory profiles of the farmhouse and industrial cheeses were significantly different, regardless of the time of the year and ripening time. The results for the principal component analysis (PCA) performed on the sensory attributes of the cheese samples showed two PCs defined as ‘farmhouse flavour factor’ and ‘industrial flavour factor’. Farmhouse cheeses showed high scores for buttery, milky and toasty odours, and buttery and nutty flavours, whereas industrial cheeses showed high scores for sharp, rennet and brine odours, and rennet and rancid flavours. The percentages of methyl ketones such as 3‐hydroxy‐2‐butanone, 2‐butanone, 2‐pentanone and 2‐heptanone, and acids such as n‐propanoic, 2‐methylpropanoic and 3‐methylbutanoic acids were higher in farmhouse cheeses than in industrial cheeses. On the other hand, the percentages of esters such as ethyl butanoate and ethyl hexanoate, and alcohols such as 3‐methyl‐1‐butanol, and acids like n‐hexanoic acid were higher in industrial cheeses than in farmhouse cheeses. Relationships between sensory attributes and volatile compounds were studied on the basis of the differences found in sensory profile and volatile composition between farmhouse and industrial cheeses. Copyright © 2005 Society of Chemical Industry