Effect of different levels of fat and inulin on the microbial growth and metabolites in probiotic yogurt containing nonviable bacteria

Effects of different levels of fat and inulin on bacterial cell counts, degree of proteolysis and concentrations of organic acids in the yogurt containing inactivated cells of probiotic strains Bifidobacterium animalis and Lactobacillus acidophilus were investigated. Results showed that both L. acidophilus and B. animalis grew well in the yogurt samples reaching cell counts higher than 10⁶ CFU mL^?1 at the final pH of 4.5. Inulin at the concentration of 1% had no significant effects on the production of organic acids and cell counts of L. acidophilus, but promoted the growth of B. animalis with a reduction in the degree of proteolysis. Generally, different fat levels showed significant effects on the production of organic acids and nonsignificant effects on the cell counts of probiotic bacteria and degree of proteolysis. In case of lactic acid, the ratio of L‐ (+)to D‐ (?) isomer ranged from 50/50 to 80/20 in yogurt samples.     

Case study: Comparison of milk composition from adjacent organic and conventional farms in the USA

A study of two adjacent dairy farms, one using conventional confined herd management and the other organic management, revealed significant differences in the fatty acid composition of the milk. Compared with conventional milk, organic milk had higher levels of conjugated linoleic acid (CLA) and α‐linolenic acid (the major omega‐3 fatty acid in milk), and less stearic and linoleic acid (the major omega‐6 fatty acid in milk) during the spring–summer grazing season. When discarding geography and weather as variables, organic milk appears to yield more CLA and α‐linolenic acid, which should be beneficial to health.     

The chemical composition of different edible locations (central and edge muscles) of flat fish (Lepidorhombus whiffiagonis)

The chemical composition of the different edible locations (central and edge muscles) of a flat fish (megrim, Lepidorhombus whiffiagonis) was comparatively analysed at both body sides. Higher moisture and lower lipid contents were obtained in central muscles than in edge ones. Edge sites showed higher triacylglycerols and sterols contents and lower mean phospholipids values than central muscles. A higher α‐tocopherol presence was observed in the lipid fraction of central muscles than in the edge ones. For both fish sides, fatty acid (FA) analysis showed lower monounsaturated FA and higher polyunsaturated FA contents and ω3/ω6 ratios in central muscles. Presence of essential elements (Co, Cu, Mn, Se, Zn) did not provide differences among sites considered. Concerning toxic elements, As content showed greater levels in central muscles than in their corresponding edge sites for both fish sides, upper zones showed higher mean scores in As, Cd, Cr, Hg, Ni, Pb and V.     

碳源对裂殖壶菌类胡萝卜素积累的影响

本文研究了葡萄糖和甘油分别作为单一碳源对裂殖壶菌ATCC20888发酵过程中脂质和类胡萝卜素变化特性的影响,初步讨论了在裂壶藻中类胡萝卜素与脂质代谢之间的关系。结果表明,作为碳源,葡萄糖相比甘油更有利于菌体生长,而甘油更有利于脂质,尤其是DHA的积累。此外,碳源不同,总类胡萝卜素的含量及组成也会因此而不同。当发酵7 d时,以甘油作碳源发酵得到的β-胡萝卜素含量是以葡萄糖作碳源时的3.25倍。而以葡萄糖为碳源发酵得到的番茄红素和虾青素含量分别是甘油发酵1.60倍和2.81倍。并且,在不同碳源发酵条件下,进入脂质反耗阶段后,菌体内PKS途径的脂肪酸比例均与总类胡萝卜素含量呈正相关,因此表明类胡萝卜素对细胞内多不饱和脂肪酸的稳定性发挥着积极作用。      

Characterisation of yoghurt enriched with polyunsaturated fatty acids by using walnut slurry

This study aimed to evaluate the physicochemical, chemical, rheological, sensorial and microbiological properties of yoghurt enriched with polyunsaturated fatty acids (PUFAs). The PUFA‐enriched yoghurt was prepared with walnut slurry (10%?50%) and skimmed milk (50%?90%). Compared with the control yoghurt, it contained a lower content of protein, potassium, sodium and phosphorus, and a higher content of fat, iron, magnesium and zinc. Moreover, it exhibited a lower syneresis value and a higher water‐holding capacity value. Its fat was rich in omega fatty acids, mainly linoleic and linolenic acids. These research findings revealed that walnut slurry could be used in yoghurt manufacture to develop fermented milk products as functional foods, especially when enriched with omega fatty acids.     

Effect of increasing amounts of a linoleic-rich dietary fat on the fat composition of four pig breeds. Part I: Backfat fatty acid evolution

Four diets prepared, respectively, with 0%, 2%, 4% and 8% of a high-linoleic added fat were administered (76 days of treatment) to a sample of 112 pigs of four breeds (Landrace, Large White, Duroc and a crossbreed Landrace × Duroc). The effects of diet and breed on the evolution of the fatty acid composition of backfat were examined by taking biopsies. Over time, a continuous increase in stearic, palmitic and oleic acids throughout the pig’s life was observed. Oleic acid showed the smallest differences among the four diets at the end of the experiment, while stearic and palmitic acid showed higher differences according to the increase in the percentage of dietary fat. Stearic acid showed the highest rate of increase over time, according to the increasing intake of linoleic acid (diets 1–4). These increases were compensated by a decrease in linoleic acid, although this decrease tended to stabilize according to a higher percentage of added fat and also, for diet 4 (8% fat), an increase in linoleic acid was observed at the end of the experiment. Among the minor fatty acids, arachidonic acid showed a clear decrease over time, although higher levels at the end of the experiment were observed for diets including 4% and 8% of added fat, compared to the other two diets including lower amounts of linoleic acid. Moreover, a significant effect was observed for the factor breed. So, Duroc pigs showed the highest rate of deposit of linoleic acid and the lowest of stearic acid, while the other three breeds showed similar rates.     

亚麻籽降鸡血脂作用的研究

在鸡饲料中添加富含多不饱和脂肪酸(PUFAs)的亚麻籽,观察其对鸡血清总胆固醇(TC)、甘油三脂(TG)的影响,并与常规饲料组进行比较。选产蛋鸡20只,分为4组(对照组和添加低、中、高剂量亚麻籽组),喂养4个月,测定鸡血清中TC、TG含量。结果表明:添加低、中、高剂量亚麻籽组鸡血清中TC均显著低于常规饲料组(P<0.05);高剂量组鸡血中的TG显著低于常规饲料组(P<0.05)。因此,富含n-3多不饱和脂肪酸(PUFAs)的亚麻籽具有良好的降低血脂的作用,值得进一步研究和开发。     

Antiglycation capacity and antioxidant activities of different pigmented Thai rice

This study investigated the antiglycation capacity and antioxidant activities of fifteen Thai rice varieties. Purple variety, Kum Rai showed the highest value of total phenolic content (245.06 ± 7.87 mg GAE/gram extract dry weight), DPPH radical scavenging activity (92.33 ± 0.49 mg Trolox/gram extract dry weight), ABTS radical scavenging activity (221.01 ± 0.25 mg Trolox/gram extract dry weight) and percentage inhibition of AGEs formation (82.03 ± 0.19%). We found that, total phenolic content and antioxidant activities (ABTS and DPPH assay) in rice varieties were highly correlated (P < 0.05) with their antiglycation capacity. These results indicated that the total phenolic content was responsible for antioxidant and antiglycation capacities of rice samples. This study is the first report on a correlation between anti‐AGEs capacity and antioxidant activities of Thai rice varieties. Our data have provided useful information for selection of rice varieties for the bioactive compounds that may improve the health of the aged and diabetic complications.     

Optimisation of analytical methods for the characterisation of oranges,clementines and citrus hybrids cultivated in Spain on the basis of their composition in ascorbic acid,citric acid and major sugars

Three HPLC methods were optimised for the determination of citric acid, succinic acid and ascorbic acid using a photodiode array detector and fructose, glucose and sucrose using a refractive index in twenty eight citrus juices. The analysis was completed in <16 min. Two different harvests were taken into account for this study. For the season 2011, ascorbic acid content was comprised between 19.4 and 59 mg vitamin C/100 mL; meanwhile for the season 2012, the content was slightly higher for most of the samples ranging from 33.5 to 85.3 mg vitamin C/100 mL. Moreover, the citric acid content in orange juices ranged between 9.7 and 15.1 g L^?1, while for clementines the content was clearly lower (i.e. from 3.5 to 8.4 g L^?1). However, clementines showed the highest sucrose content with values near to 6 g/100 mL. Finally, a cluster analysis was applied to establish a classification of the citrus species.     

Influence of different preservation treatments on the volatile fraction of desalted cod

In the present study, desalted cod underwent a water blanching treatment and the incorporation of additives (citric acid and potassium sorbate), combined with different types of packaging (air, vacuum and modified atmosphere), to achieve an improvement of the shelf life of ready-to-use desalted cod. The purpose of this work was to evaluate the effect of these combined methods of preservation on the volatile fraction of desalted cod during 42 days in cold storage. The volatile compounds identified in all samples were those mainly related to fresh odor in whitefish, although with some exceptions. Untreated desalted cod showed a high increase of 3-methyl-1-butanol (described as a microbial spoilage index) during the storage period; a higher increase in air packaging than in vacuum and modified atmosphere packaging. The slow increase of this compound, as well as the evolution of ketones and aldehydes observed for the rest of the samples submitted to treatment, demonstrated the effectiveness of the combined treatments applied. The most efficient treatment was the combination of additives together with modified atmosphere packaging.     

Cranberry seed fibre: a promising prebiotic fibre and its fermentation by the probiotic Bacillus coagulans MTCC 5856

Cranberry, a versatile fruit, is known for nutritional as well as medicinal properties due to the presence of bioactive compounds. However, cranberry fruit has not been fully explored for its prebiotic potential. Therefore, this study was conducted to evaluate prebiotic potential of cranberry seed fibre (CSF) and also evaluate its fermentability by the probiotic strain Bacillus coagulans MTCC 5856. The resistance to gastric acid and porcine pancreatic enzymatic (PPE) hydrolysis of CSF was investigated using an in vitro model. It was found that CSF was resistant to gastric acid and also nondigestible to PPE hydrolysis. CSF as sole nutrition source was evaluated for the fermentability by B. coagulans MTCC 5856. A significant amount of short‐chain fatty acids was produced by the B. coagulans MTCC 5856 while fermenting cranberry fibres anaerobically. CSF supported the growth of B. coagulans MTCC 5856 and also inhibited the growth of E. coli ATCC 25922 when cocultured in an anaerobic environment. CSF from the cranberry fruit exhibited prebiotic potential and also found to be fermentable by B. coagulans MTCC 5856. This study provided the scientific evidence of CSF as a prebiotic fibre and also its suitability with the probiotic B. coagulans MTCC 5856 for an ideal synbiotic preparation.     

Effect of nisin‐producing Lactococcus lactis starter cultures on the inhibition of two pathogens in ripened cheeses

The effect of Lactococcus lactis nisin‐producing strains, isolated from Italian fermented foods, on the survival of two foodborne pathogens namely Listeria monocytogenes and Staphylococcus aureus was investigated in experimental cheese production. One of the three Lactobacillus lactis nisin innoculated as starters, Lactobacillus lactis 41FL1 lowered S. aureus count by 1.73 log colony‐forming units (cfu)/g within the first 3 days, reaching the highest reduction, 3.54 log cfu/g, by the end of ripening period of 60 days. There was no effect on L. monocytogenes. The application of L. lactis 41FL1 as bioprotective culture in controlling S. aureus shows considerable promise.     

Production of Agaricus brasiliensis mycelium from food industry residues as a source of antioxidants and essential fatty acids

Agaricus brasiliensis is a medicinal mushroom traditionally employed in prevention and treatment of cancer, used as immunostimulant and as a source of antioxidants. We investigated the chemical composition of the mycelium produced by submerged (SF) and solid‐state fermentation (SSF), using residues from food industry as substrates. After fermentation, antiradical activity and levels of antioxidants were enhanced, indicating that the micro‐organism produces these metabolites. For myceliated substrate (mushroom mycelia grown around and into the substrate particles) obtained by SSF, phenolics ranged from 18.57 to 70.46 mg g^?1 and flavonoids from 0.83 to 4.51 mg g^?1. For myceliated substrate obtained by SF, the variation was 27.19 to 66.99 mg g^?1 and 0.75 to 5.34 mg g^?1 for phenolics and flavonoids, respectively. The fatty acid profile determined by FT‐ICR MS and UPLC‐MS showed predominance of palmitic, linoleic, linolenic and oleic acids. Our findings indicated that mycelium has nutraceutical potential and can be incorporated in food supplements.     

Polyphenolic and phytochemical content of Cucumis sativus seeds and study on mechanism of preservation of nutritional and quality outcomes in enriched mayonnaise

Oxidative rancidity in food emulsions leads to a reduction in shelf life. Synthetic antioxidants are widely used in food industry to prevent the development of rancidity. The present study was focussed on investigating the antioxidant potential of Cucumis sativus seeds (CSS) and correlates these findings with mayonnaise enrichment and extends its shelf life. CSS exhibited the highest abundance in phenolic compounds (93.5 ± 0.1 mgGAE g^?1), flavonoids (57.4 ± 0.1 mgQE g^?1), β‐carotene (19.46 ± 0.4 mg carotenoids per 100 g) and high free radical scavenging activity. CSS (200 ppm) and butylated hydroxyanisole (200 ppm) were incorporated in mayonnaise and the oxidative stability was evaluated by peroxide, p‐anisidine and TBARS values during storage at different temperatures. Organoleptic evaluations indicated that CSS enriched sample was recorded the highest overall acceptability. The results from our study will provide scientific basis for CSS as natural preservative against lipid oxidation or food enrichment while developing functional foods.     

Differential scanning calorimetry evaluation of oxidation stability of docosahexaenoic acid in microalgae cells and their extracts

The aim of this work was to evaluate the oxidative stability of docosahexaenoic acid (DHA) from Aurantiochytrium limacinum SR21 microalgae cells and in their lipidic extract by differential scanning calorimetry (DSC). Besides, freezing was evaluated as a strategy for microalgal DHA long‐term conservation by analysing changes in their thermal properties. As a first approach, mixtures of the most representative A. limacinum SR21‐fatty acids were evaluated in model systems. DHA and palmitic acid were the major polyunsaturated and saturated fatty acids produced by the microalgae cells, respectively. Changes in DHA/palmitic acid ratio in model systems, in cells and their lipidic extracts, were detected by DSC through shifts in the oxidation onset temperature (OOT) values. However, OOT values of cells and lipidic extracts could be also influenced by cellular compartmentalisation, carotenoids and other components presence. Freezing was not a good strategy for DHA long‐term conservation, as revealed by OOT values and thermal properties, which reflected the extensive changes that occurred during storage.     

Determination of the relationship between oxalate degradation and exopolysaccharide production by different Lactobacillus probiotic strains

The aim of this study was to evaluate the protective effects of exopolysaccharide (EPS) production on resistance to gastrointestinal digestive conditions and oxalate by probiotic strains of the species Lactobacillus rhamnosus, Lactobacillus fermentum and Lactobacillus brevis. The oxalate‐degrading ability of the strains was determined using an enzymatic assay. The correlation between oxalate degradation rate and EPS production was not significant (P > 0.05); however, the high‐EPS‐producing L. fermentumIP5 and L. brevisYG7 strains showed high oxalate‐degrading activity, whereas the low‐EPS‐producing strain L. fermentumBP5 demonstrated low oxalate‐degrading activity. The present findings suggest that dietary supplementation with the probiotic strain L. fermentumIP5 could be a promising strategy for the prevention of oxalate stone disease.     

Changes in the composition of the fatty acids and aldehydes of meat lipids after heating

The effects of heating at 132°C on the fatty acids and fatty aldehydes of neutral lipids and phospholipids of lean beef, veal, lamb, pork and chicken were studied. Heating caused hydrolysis of the plasmalogens in the phospholipids, and varying amounts of the liberated fatty aldehydes were recovered in the neutral lipid fractions. Beef phosphatidyl choline lost more polyunsaturated fatty acids than that of the other meats. Beef and veal phosphatidyl ethanolamine lost more polyunsaturated fatty acid than that of lamb, pork or chicken, but the effect was obscured by the influx of fatty acids from elsewhere into this fraction after heating.