Evaluation of the use of attenuated total reflectance mid infrared spectroscopy to determine fatty acids in intact seeds of barley (Hordeum vulgare)

Attenuated total reflectance (ATR) mid-infrared (MIR) spectroscopy was evaluated to measure fatty acids (FA) and total lipids in intact seed barley (Hordeum vulgare) samples. Results from this study demonstrated the capability of ATR-MIR spectroscopy coupled with partial least squares (PLS) regression to measure FA non-destructively in intact barley seeds. The coefficients of determination in cross validation (R²) and the standard error of cross validation (SECV) were 0.76 and 0.004 g 100 g⁻¹ for stearic, 0.75 and 0.037 g 100 g⁻¹ for oleic, 0.45 and 0.02 g 100 g⁻¹ for palmitic acids, and 0.89 and 0.13 g 100 g⁻¹ for total lipids, respectively. The practical implications of this study showed that ATR-MIR spectroscopy confer valuable benefits for the grain industry and in particular in breeding programs as a non-destructive high throughput method.     

麦绿素对大鼠的降血脂作用实验研究

为研究麦绿素对大鼠的降血脂作用,以0.33、1.00、3.00 g/kg BW d^-1剂量的麦绿素灌胃给予Wistar雄性大鼠30 d,于试验开始及结束时测试TG、TC及HDL-C,观察不同剂量的麦绿素对高脂饲料喂养大鼠血脂的影响.大鼠连续灌胃给予麦绿素30 d后,1.00、3.00 g/kg BW d^-1剂量组的血清TC及3.00 g/kg BW d^-1剂量组的血清TG显著低于对照组（P〈0.05）,各剂量组的血清HDL-C无明显变化（P〉0.05）.在本试验条件下,麦绿素对大鼠具有降血脂作用。     

Amounts of conjugated linoleic acid (CLA) in German foods and evaluation of daily intake

 The quantities of the biologically active isomer of conjugated linoleic acid (CLA) – C18:2 c9t11 – in 139 German foods were analysed by capillary gas chromatography (results are given as a % of all identified fatty acid methyl esters). The CLA content ranged from 0.40% (Gouda) to 1.70% (Jurassic cheese, Old Emmentaler) in dairy products, from 0.11% (rabbit) to 1.20% (lamb) in meat, and from 0.01% (pike-perch) to 0.09% (carp) in fish. CLA could be detected in neither vegetable fats or oils nor in margarines (CLA <0.01%). Crisps, chocolates, cakes and pastries, and other foods have only a negligible CLA content. The average estimated CLA intake in Germany was calculated to be 0.35g CLA/day for women and 0.43g CLA/day for men. Received: 22 July 1997     

Oxidative stability and total lipids on thigh and breast meat of broilers fed diets with two fat sources and supplemented with conjugated linoleic acid

Two hundred broiler chickens of 21 days of age were distributed in a completely randomized factorial arrangement 2×5 (two oil sources, i.e. soybean or canola oil and five levels of CLA supplementation, i.e. 0.0%, 0.25%, 0.50%, 0.75% and 1.00%). The purpose of this study was to evaluate the dietary supplementation of broiler diets with CLA and oil sources on the lipid content and on the oxidative stability of chicken meat submitted to refrigeration or freezing storage temperatures. The use of canola oil and increasing CLA levels resulted in a linear reduction (P<0.05) on the total lipids in breast meat. These results can explain a linear reduction (P<0.05) observed in the malonaldehyde content of refrigerated and frozen meat of birds receiving canola oil. Birds receiving soybean oil and supplemented with CLA showed an abrupt reduction of total lipids on breast meat from 0.89 g/100 g at 0% CLA to 0.36 g/100 g at 0.5% CLA followed by a small increase at higher levels of CLA (P<0.05). These observations may help to explain the reduction (P<0.05) of oxidation in breast meat during frozen storage at 50 and 100 days as well as during cold storage at 5 °C.     

Separation of nickel catalyst by microfiltration

Ceramic membranes with pore size of 0.1 and 0.2 µm are used for the separation of nickel catalyst. Effect of trans‐membrane pressure (TMP), linear velocity, temperature and nickel content (solute) on flux and rejection has been investigated. The flux increased with increase in pore size of the membrane. The rejection characteristics were similar for 0.1 and 0.2 µm membranes. The nickel content and iodine value of the membrane‐filtered oil was comparable with that of conventional processes. Permeate flux increased with increase in temperature. Flux increased with increase in linear velocity and a marginal rise was observed above 2.09 m/s. The rejection characteristics were only slightly affected by higher linear velocity. The flux improved after back flushing. The average flux was higher with back flushing as compared to continuous (with out back flushing) filtration process. The results indicated that the secondary layer effect was more pronounced in microfiltration. The flux decreased with increase in solute concentration. The rejection characteristics were not affected by solute concentration. The rejection characteristic of the membranes remained unaltered after membranes were repeatedly cleaned with sodium hydroxide and HCl solutions, however, the flux was decreased marginally.     

Structural and biochemical characteristics of bovine intramuscular connective tissue and beef quality

The aim of the study was to evaluate the impact of structural and biochemical characteristics of muscle intramuscular connective tissue on beef quality. The experimental design was based on three muscles of three breeds sampled as fresh material and cooked at 55 °C (Longissimus thoracis and Semimembranosus) or at 70 °C (Semimembranosus and Biceps femoris) for quality assessment. The results showed that muscle characteristics influence beef quality differently from one muscle to another. In grilled LT, proteoglycan content contributed negatively to juiciness, and intramuscular lipids were linked positively to tenderness, flavour, residues and overall liking scores. In grilled SM, cross-link and lipid contents were involved in beef quality. In BF cooked to 70 °C, perimysial branch points were negatively linked to tenderness. In SM cooked to 70 °C, perimysial area was involved in beef quality. These results should allow a better understanding of the factors involved in background toughness, in juiciness and flavour of meat.     

构造脂质的开发概况

概述了构造脂质－甘油三酸酯（包括巧克力用油脂、易消化性油脂、低热量油脂以及高氧化稳定性油脂等）的消化吸收特性以及生理作用,还介绍了几种构造脂南的开发概况。     

Supercritical Fluid Extraction and Chromatography of Lipids in Bilberry

A supercritical fluid extraction (SFE) method has been developed for the extraction of lipids in bilberry. Experimental design was used to optimize pressure, temperature and extraction time using CO₂ as solvent. Best SFE condition for total lipids was 450 bar, 60 °C and 45 min. The SFE method was compared to conventional Bligh & Dyer (B&D) extraction. The amount of fatty acid methyl esters (FAME) was found to be 4.84 ± 0.06 mg and 4.564 ± 0.003 mg per g of the freeze‐dried bilberry sample for the developed SFE and B&D methods, respectively, while the amount of total lipids was found to be 54.40 ± 6.06 mg and 65.70 ± 0.67 mg per g of sample for SFE and B&D, respectively. This discrepancy between FAME and total lipids could be explained by the presence of wax esters, sterol esters, carotenoids and phospholipids, as determined by supercritical fluid chromatography.     

Biodiesel production by microalgal biotechnology

Biodiesel has received much attention in recent years. Although numerous reports are available on the production of biodiesel from vegetable oils of terraneous oil-plants, such as soybean, sunflower and palm oils, the production of biodiesel from microalgae is a newly emerging field. Microalgal biotechnology appears to possess high potential for biodiesel production because a significant increase in lipid content of microalgae is now possible through heterotrophic cultivation and genetic engineering approaches. This paper provides an overview of the technologies in the production of biodiesel from microalgae, including the various modes of cultivation for the production of oil-rich microalgal biomass, as well as the subsequent downstream processing for biodiesel production. The advances and prospects of using microalgal biotechnology for biodiesel production are discussed.