This research paper addresses the hypothesis that the optimum doses of a continuous type of ultraviolet (UV) light applied to the surface of lor (whey) cheese needs to be identified to maximize mould inactivation and shelf life while minimizing quality deterioration. Therefore, the mould inactivation, protein and lipid oxidation products, sensory and colour attributes of lor cheese subjected to different doses of UV light (1.617, 4.018, and 36.832 kJ/m2) in a continuous type of UV system were evaluated. UV treated samples presented mould counts lower than those of untreated ones. UV treatment at more than 4.018 kJ/m2 allowed around 0.7–2.7 log reductions on mould growth during storage. The increase in UV light dose caused significant increases in primary and secondary lipid oxidation products. In particular, the highest doses applied to the surface of cheese samples had the highest values of protein carbonyls, as well as lipid oxidation products. Strong positive correlations were recorded between lipid and protein oxidation markers. Exposure to the highest doses of UV light increased foreign flavour perception, probably due to the oxidative reactions. The results indicated that the application of UV light to the lor cheese surface allowed delaying mould growth during storage but extreme doses could induce lipid and protein oxidation reactions, leading to quality deterioration.

This research paper addresses the hypothesis that the application of ultraviolet (UV) light before packaging of pasta-filata cheese has the potential to eliminate or control post-processing contamination whilst maintaining chemical and sensorial quality. The surfaces of kashar cheese were treated at different doses of UV light (0.32–9.63 kJ/m2) in a batch UV cabinet system to determine effects on physicochemical and sensorial quality as well as mould inactivation. Untreated cheese samples were also used for comparison. Kashar cheese was naturally contaminated in a mouldy environment to provide the desired mould numbers before UV treatments. Log reductions of 0.34, 0.69 and 2.49 were achieved in samples treated at doses of 0.32, 0.96 and 1.93 kJ/m2, respectively and the mould count of sample treated at 9.63 kJ/m2 was below the detection limit. We found no significant differences in composition and hardness values between any of the treated or control cheeses. Although some individual colour values increased as the UV doses increased, this change was not observed visually in sensory analysis. Increased light intensity accelerated the lipid oxidation causing a perception of off-flavour. The results of this study show that it is necessary to examine the relationship between the oxidative and sensory interactions while determining the effective doses applied to cheese surface for microbial inactivation.

Finishing late-maturing bulls on grass may alter the antioxidant/prooxidant balance leading to beef with higher susceptibility to lipid oxidation and a lower colour stability compared to bulls finished on cereal concentrates. In this context, lipid oxidation and colour stability of beef from late-maturing bulls finished on pasture, with or without concentrate supplements, or indoors on concentrate was assessed. Charolais or Limousin sired bulls (n = 48) were assigned to four production systems: (1) pasture only (P), (2) pasture plus 25% dietary DM intake as barley-based concentrate (PC25), (3) pasture plus 50% dietary DM intake as barley-based concentrate (PC50) or (4) a barley-based concentrate ration (C). Following slaughter and postmortem ageing, M. Longissimus thoracis et lumborum was subjected to simulated retail display (4°C, 1000 lux for 12 h out of 24 h) for 3, 7, 10 and 14 days in modified atmosphere packs (O2 : CO2; 80 : 20). Lipid oxidation was determined using the 2-thiobarbituric acid-reactive substances assay; α-tocopherol was determined by HPLC; fatty acid methyl esters were determined using Gas Chromatography. Using a randomised complete block design, treatment means were compared by either ANOVA or repeated measures ANOVA using the MIXED procedure of SAS. Total polyunsaturated fatty acid (PUFA) concentrations were not affected by treatment, n-3 PUFAs were higher (P < 0.001) and the ratio of n-6 to n-3 PUFAs was lower (P < 0.001) in muscle from P, PC25 and PC50 compared to C. α-Tocopherol concentration was higher in muscle from P compared to PC50 and C bulls (P = 0.001) and decreased (P < 0.001) in all samples by day 14. Lipid oxidation was higher in muscle from C compared to P bulls on day 10 and day 14 of storage (P < 0.01). Finishing on pasture without supplementation did not affect beef colour stability and led to lower lipid oxidation, possibly due to the higher α-tocopherol concentration compared to concentrate finished beef.

The cryopreservation of epididymal sperm is an important technique that allows genetic material to be preserved, even post mortem. However, cryopreservation leads to increased oxidative stress and impaired sperm viability. Polyunsaturated fatty acid (PUFA) supplementation may improve certain sperm characteristics, but it also makes sperm more susceptible to oxidative stress, therefore adding antioxidants that counteract oxidative stress has become an option. In this context, this study aimed to evaluate the effect of the interaction between docosahexaenoic acid (DHA) and antioxidants on the quality after the cryopreservation of epididymal bull sperm. Twenty epididymides were collected after slaughter, and epididymal sperm was cryopreserved with bovine extender supplemented with docosahexaenoic acid (DHA), glutathione peroxidase (GPx) and superoxide dismutase (SOD). We verified an improvement in motility in the group that was treated only with DHA 5 µM and a concentration-dependent effect on susceptibility to lipid peroxidation that was associated with DHA concentration (1 µM, 5 µM or 10 µM). Moreover, treatment with DHA (5 µM) and SOD (20 IU/ml) resulted in higher sperm motility. Thus, the association between DHA (5 µM) and SOD (20 IU/ml) appears to be an option for increased epididymal sperm features in bulls.

The study aimed to examine the effects of diurnal Ramadan fasting (RF) on substrate oxidation, energy production, blood lipids and glucose as well as body composition. Nine healthy Muslim men (fasting (FAST) group) and eight healthy non-practicing men (control (CNT) group) were assessed pre- and post-RF. FAST were additionally assessed at days 10, 20 and 30 of RF in the morning and evening. Body composition was determined by hydrodensitometry, substrate oxidation and energy production by indirect calorimetry, blood metabolic profile by biochemical analyses and energy balance by activity tracker recordings and food log analyses. A significant group×time interaction revealed that chronic RF reduced body mass and adiposity in FAST, without changing lean mass, whereas CNT subjects remained unchanged. In parallel to these findings, a significant main diurnal effect (morning v. evening) of RF on substrate oxidation (a shift towards lipid oxidation) and blood metabolic profile (a decrease in glucose and an increase in total cholesterol and TAG levels, respectively) was observed, which did not vary over the course of the Ramadan. In conclusion, although RF induces diurnal metabolic adjustments (morning v. evening), no carryover effect was observed throughout RF despite the extended daily fasting period (18·0 (sd 0·3) h) and changes in body composition.

Data are scarce regarding combined high Se and Mn supplementation in livestock diets, however, as Se and Mn are functionally related as cofactors of glutathione peroxidase (GPx) and Mn-superoxide dismutase (SOD), respectively, beneficial synergistic effects on oxidative stability of tissues may result. This experiment evaluated the effect of an oversupply of Se and Mn within European legal limits compared with recommendations on performance, oxidative stability of the organism and meat quality in a randomised complete block design. A total of 60 crossbred gilts were fed maize–barley–soya bean meal diets formulated in a 2×2 factorial approach with inorganic Se (0.2 v. 0.5 mg/kg Se dry matter (DM)) or inorganic Mn (20 v. 150 mg/kg Mn DM) from 31 to 116 kg BW. Se supplementation reduced feed intake, whereas high Mn diets impaired average daily gain (P<0.05). Qualitative carcass characteristics were impaired by Se and Mn predominantly in the semimembranosus muscle. Activity of GPx in liver was increased by high Se diets (P<0.05). Mn supplementation increased catalase (CAT) activity in liver, GPx in plasma and total antioxidative capacity (TAC) in muscle, whereas it decreased CAT activity in plasma (P<0.05). Cu/Zn-SOD in muscle showed higher activity in high-Se-low-Mn diets but lower activity when both high Se and Mn were combined (Se×Mn P<0.05). Mn supplementation increased Mn concentration in longissimus thoracis et lumborum, but simultaneously reduced Se concentration (P<0.05). Upon retail display, Mn increased lipid oxidation more pronouncedly (higher thiobarbituric acid reactive substances; P<0.05) than Se (P<0.10). Despite some positive effects (Mn increased TAC, Se increased GPx, Se and Mn increased tenderness), no synergistic effects of high Se and Mn diets or an overall beneficial impact on meat quality, especially during storage, could be observed. Including the negative effects on performance, feeding Se and Mn up to the maximum legal level cannot be recommended.

The valorization of spent hens via the food chain has some major limitations, which include low meat yield and tough meat. The latter issue can be overcome by producing convenience foods; the first may be alleviated by employing a genotype with higher meatiness. To quantitatively compare two common layer genotypes in production performance, meat yield and sausage quality, 2200 57 weeks old Institut de Sélection Animale (ISA) Warren and Dekalb White hens each were investigated during the last 60 days of egg laying. The hens were housed in an aviary system in 2×10 compartments (10 compartments/each genotype). Measurements included feed intake, laying performance, egg weight and feed conversion ratio as measured per compartment. BW was determined twice on 10 animals per compartment. Finally, two sub-groups of five hens per compartment were slaughtered, meat yield was recorded and bratwurst-type sausages were produced (n=20 per genotype). Fat proportion, cooking loss, connective tissue properties and Kramer shear energy were measured. After 1, 4, 7 and 10 months of frozen storage, oxidative stability (thiobarbituric acid reactive substances (TBARS)) and microbiological status were determined as shelf-life related criteria. ANOVA was performed considering genotype as the main effect. The ISA Warren hens were inferior in laying performance (−11%) and feed conversion ratio (+10%) compared with Dekalb White, but had the same feed intake. The ISA Warren had higher BW and carcass weight than the Dekalb White. Carcass yield was higher by 5.9%. There were 80 g (23%) more meat available for sausage production from ISA Warren compared with Dekalb White. Sausages prepared from meat of ISA Warren hens contained less fat than those from Dekalb White, but showed the same cooking loss. Although the collagen proportion of the sausages produced from ISA Warren was lower than from Dekalb White, collagen solubility was lower and shear energy was higher. During the 10 months of frozen storage, TBARS increased continuously, but not to an extent that would prevent its use as food. The sausages from the ISA Warren genotype had marginally higher TBARS levels during storage. Total colony counts decreased with storage time, with slightly lower values found in the non-spiced sausage material from the ISA Warren hens. In conclusion, when intending to use spent hens as food, ISA Warren are clearly superior to Dekalb White in meat and sausage yield. When processing the meat to sausages, the higher shear energy is probably advantageous.

Flavour, one of the most important factors affecting consumers’ meat-buying behaviour and preferences, comprises mainly of taste and aroma. The cooked meat flavour, that is important from the producer and consumer point of view, is affected by several pre- and post-slaughter factors, including breed, diet, post-mortem ageing, and method of cooking. Moreover, chicken meat is prone to the development of off-flavours through lipid oxidation, which reduce the quality of the chicken meat. The aim of this review is to discuss the main factors affecting cooked chicken meat flavour which helps producers and consumers to produce the most flavoured and consistent product possible. Cooked chicken meat flavour is thermally derived via the Maillard reaction, the degradation of lipids, and interaction between these two reactions. Factors affecting the flavour of cooked chicken meat were identified as breed/strain of the chicken, diet of the bird, presence of free amino acids and nucleotides, irradiation, high pressure treatment, cooking, antioxidants, pH, and ageing.

Limited – though increasing – evidence suggests that argan oil might be endowed with potential healthful properties, mostly in the areas of CVD and prostate cancer. We sought to comprehensively determine the effects of argan oil supplementation on the plasma lipid profile and antioxidant status of a group of healthy Algerian subjects, compared with matched controls. A total of twenty healthy subjects consumed 15 g/d of argan oil – with toasted bread – for breakfast, during 4 weeks (intervention group), whereas twenty matched controls followed their habitual diet, but did not consume argan oil. The study lasted 30 d. At the end of the study, argan oil-supplemented subjects exhibited higher plasma vitamin E concentrations, lower total and LDL-cholesterol, lower TAG and improved plasma and cellular antioxidant profile, when compared with controls. In conclusion, we showed that Algerian argan oil is able to positively modulate some surrogate markers of CVD, through mechanisms which warrant further investigation.

Nutritional value is a priority in new product development. Using vegetable or marine oils, rich in polyunsaturated fatty acids, in dairy beverage formulations is an option to provide the consumers with healthier products. However, these formulations are prone to oxidation, which is responsible for rapid flavour degradation and the development of potentially toxic reaction products during storage. Flaxseed lignans, secoisolariciresinol diglucoside (SDG), and its mammalian metabolites have antioxidant activity and could be used in beverage formulations to prevent oxidation. Commercially available SDG extract was added to the formulation of dairy beverages enriched with flaxseed oil. As an alternative approach, dairy beverages were produced from milk naturally rich in SDG metabolites obtained through the alteration of cow diet. Resistance to oxidation was determined from the kinetics of hexanal and propanal production during heat and light exposure treatments. Increasing SDG concentration in dairy beverage slightly reduced redox potential but had no effect on oxygen consumption during oxidation treatments. The presence of SDG in dairy beverage significantly improved resistance to heat- and light-induced oxidation. However, purified enterolactone, a mammalian metabolite from SDG, prevented oxidation at much lower concentrations. The use of milk from dairy cow fed flaxseed meal did not improve resistance to oxidation in dairy beverage. Enterolactone concentration in milk was increased by the experimental diet but it remained too low to observe any significant effect on dairy beverage oxidation.

On the premise that seed ageing may be largely a result of free-radical lipid autoxidation, a study was made of the relationship between lipid stability and longevity in seeds of soybean (Glycine max), lentil (Lens culinaris), mungbean (Vigna radiata), chickpea (Cicer arietinum), broadbean (Vicia faba), pea (Pisum sativum), lettuce (Lactuca sativa), and tomato (Lycopersicon esculentum). Seed lipids were examined for α-, γ- and δ-tocopherols, and levels of unsaturated and saturated fatty acids. Using this information, analysis was attempted using linear, multiplicative or exponential models to correlate aspects of lipid stability with seed longevity values from the published literature. No statistically significant correlations could be found between longevity and total lipid unsaturation, tocopherol levels or two protection formulae obtained from the oil chemistry literature. When values for tomato were excluded, a good correlation (r = 0.89, P = 0.007) was obtained using a multiplicative regression model for levels of linolenic acid per unit of total tocopherols in relation to longevity. Possible factors contributing to a lessening of the relationship between lipid stability and seed longevity are discussed.

Animal studies suggest that conjugated linoleic acid (CLA) may modulate the immune response, while studies in healthy human subjects have shown little effect and results are controversial. However, the effects of CLA may be more prominent in situations of immune imbalance, such as allergy. We studied the effects of the natural CLA isomer, cis-9, trans-11-CLA, on allergy symptoms and immunological parameters in subjects with birch pollen allergy. In a randomised, placebo-controlled study, forty subjects (20–46 years) with diagnosed birch pollen allergy received 2 g CLA/d in capsules, which contained 65·3 % cis-9, trans-11-CLA and 8·5 % trans-10, cis-12-CLA (n 20), or placebo (high-oleic acid sunflower-seed oil) (n 20) for 12 weeks. The supplementation began 8 weeks before the birch pollen season and continued throughout the season. Allergy symptoms and use of medication were recorded daily. Lymphocyte subsets, cytokine production, immunoglobulins, C-reactive protein, lipid and glucose metabolism and lipid peroxidation were assessed before and after supplementation. The CLA group reported a better overall feeling of wellbeing (P < 0·05) and less sneezing (P < 0·05) during the pollen season. CLA supplementation decreased the in vitro production of TNF-α (P < 0·01), interferon-γ (P < 0·05) and IL-5 (P < 0·05). Total plasma IgE and birch-specific IgE concentrations did not differ between groups, whereas plasma IgA (P < 0·05), granulocyte macrophage colony-stimulating factor (P < 0·05) and eosinophil-derived neurotoxin (P < 0·05) concentrations were lower after CLA supplementation. Urinary excretion of 8-iso-PGF2α, a major F2-isoprostane (P < 0·01), and 15-keto-dihydro-PGF2α, a primary PGF2α metabolite (P < 0·05), increased in the CLA group. The results suggest that cis-9, trans-11-CLA has modest anti-inflammatory effects in allergic subjects.

ApoE is secreted by macrophages at the lesion site of the atherosclerotic plaque, where it is thought to play a protective role against atherosclerosis independently of its effects on lipid metabolism. Of the three common isoforms for apoE, apoE4 is associated with higher risk of cardiovascular disease (CVD). In vitro studies have shown that recombinant apoE may act as an antioxidant in an isoform-dependent manner (E2>E3>E4). The oxidative status of the macrophages plays a key role in the process of atherosclerosis. In the present study the possible differential actions of apoE3 and apoE4 on several parameters of oxidative status were determined in stably transfected murine macrophages (RAW 264·7-apoE3 and -apoE4). No differences between genotypes were observed after peroxide challenge in either protection against cytotoxicity or in cell membrane oxidation, and modest differences were observed in the non-enzymatic antioxidants (glutathione and α-tocopherol) in apoE3 v. apoE4 macrophages. Importantly, cells secreting apoE4 showed increased membrane oxidation under basal conditions, and produced more NO and superoxide anion radicals than the apoE3 macrophages after stimulation. The present data suggest that apoE genotype influences the oxidative status of macrophages, and this could partly contribute to the higher CVD risk observed in apoE4 carriers.

The effects of dietary red pepper added to high-fat (HF) and high-carbohydrate (HC) meals on energy metabolism were examined in thirteen Japanese female subjects. After ingesting a standardized dinner on the previous evening, the subjects took an experimental breakfast (1883 kJ) under the following four conditions: HF meal, HF and red-pepper (10 g) meal, HC meal, or HC and red-pepper meal. Palatability of the experimental meals was measured immediately after the meals. Expired air was collected before and for 210 min after the meal to determine energy expenditure and macronutrient oxidation. Diet-induced thermogenesis was significantly higher after the HC meals than after the HF meals. Lipid oxidation was significantly lower and carbohydrate oxidation was significantly higher after the HC meals than after the HF meals. Addition of red pepper to the experimental meals significantly increased diet-induced thermogenesis and lipid oxidation, particularly after the HF meal. On the other hand, carbohydrate oxidation was significantly decreased by the addition of red pepper to the experimental meals. Addition of red pepper to the HC meal increased the perceived oiliness of the meal to the same level as that of the HF meals. These results indicate that red pepper increases diet-induced thermogenesis and lipid oxidation. This increase in lipid oxidation is mainly observed when foods have a HF content whereas the increase in the perceived oiliness of the meal was found under the HC meal conditions.