利用双氧水对大豆油进行脱色的实验报告

通过实验探索利用双氧水对大豆油进行脱色的工艺操作方法。经对脱色后油脂的各项理化指标及在贮藏过程中的变化情况进行测定表明,用双氧水对大豆油进行脱色是可行的。     

Ethanol animal fat emulsions as a diesel engine fuel – Part 2: Engine test analysis

This work aims on the efficient use of animal fat in a diesel engine by making its stable emulsions with ethanol and water. A single cylinder direct injection diesel engine is tested using neat diesel, neat animal fat and animal fat emulsion (optimal emulsion) as fuels under variable load operating conditions. Results show increased peak pressure and ignition delay with ethanol animal fat emulsion as compared to neat fat. Heat release pattern shows improvement in the premixed combustion phase with animal fat emulsion as compared to neat animal fat. Drastic reduction in smoke, nitric oxide, hydrocarbon and carbon monoxide emissions are observed with the emulsion as compared to neat fat and neat diesel mainly at high power outputs. Only, hydrocarbon and carbon monoxide emissions are found as high with the emulsion at light loads. In general, animal fat emulsion shows considerable reduction in all emissions and improvement in engine performance as compared to neat fat.     

Atlantic Salmon Average Fat Content Estimated by Near-Infrared Transmittance Spectroscopy

Near-infrared transmittance spectroscopy was used to determine the average fat content in farmed Atlantic salmon fillets with skin and scales. The fat content was 5.7–17.6% and weight range 1.0–5.4 kg. A partial least square regression including 43 salmon resulted in a multivariate prediction correlation of 0.97 and a root mean square error of cross validation of 0.75%. Regression models using 6 to 9 wavelengths in the 850–1048 nm range gave somewhat lower prediction errors than a model using 100 wavelengths. Results showed that NIR transmittance was suited to determine fat content nondestructively in whole salmon fillets with skin and scales.     

Effects of abomasal infusion of conjugated linoleic acid on milk fat concentration and yield from pasture-fed dairy cows

The aim of this study was to investigate the effects of conjugated linoleic acid supplementation on the synthesis of milk fat in pasture-fed Friesian cows. In four cows, a commercial mixture containing 62.3% (wt/vol) conjugated linoleic acid was infused intraabomasally to avoid rumen fermentation and biohydrogenation. The design was a 4 x 4 Latin square in which each cow received infusions of 0, 20, 40, and 80 g/d of conjugated linoleic acid mixture for 4 d. Cows were fed freshly cut ryegrass/white clover pasture ad libitum. Milk fat concentration was decreased by 36, 43, and 62% and milk fat yield was decreased by 32, 36, and 60% by the 20, 40, and 80 g of conjugated linoleic acid/d treatments. Dry matter intake, milk protein concentration, and protein yield were unaffected by treatments; however, milk yield was increased by 11% during the 40-g conjugated linoleic acid/d treatment. The effects of conjugated linoleic acid infusion were most pronounced in reducing de novo fatty acid synthesis and desaturation. Results show that the inhibitory effect of this conjugated linoleic acid mixture on milk fat synthesis occurs in pasture-fed cows, and demonstrate the potential to dramatically alter gross milk composition. This technology could offer a management tool to manipulate milk composition and energy demands of pasture-fed cows.     

Comparison of quality characteristics of full fat and low fat paneer developed from yak milk

Growing health concerns of consuming high fat products offer scope to develop low fat foods. Therefore, a study was undertaken to compare quality attributes of full fat and low fat paneer prepared from yak milk. Optimisation of fat to 1% level significantly increased density in yak milk. Moisture and ash significantly increased but yield and fat decreased in low fat yak milk paneer. No significant difference in microbial load was observed between full fat and low fat paneer. An acceptable low fat paneer with improved body and texture can be prepared with 1% fat in yak milk.     

Membrane phospholipids and sterols in microfiltered milk fat globules

Native milk fat globules of various mean diameters, ranging from d₄₃ = 2.3 µm to 8.0 µm, were obtained using microfiltration of raw whole milk. After milk fat globule washing, the milk fat globule membrane (MFGM) was separated by manual churning. After total lipid extraction and separation of polar lipids, their phospholipid (PL) and sterol composition was measured using thin‐layer chromatography, methyl ester analyses by gas chromatography, and gas chromatography coupled to mass spectrometry. The main PL species were phosphatidylethanolamine, phosphatidylcholine and sphingomyelin. The respective fatty acid composition of each PL species was measured. Many different minor bioactive sterols were detected in the MFGM, e.g. lanosterol, lathosterol, desmosterol, stigmasterol and β‐sitosterol. No significant differences in the PL and sterol profile were found between MFGM extracted from small and large milk fat globule fractions.     

冷冻调理马铃薯饼加工技术的探讨

对马铃薯的预糊化实验结果揭示,在各种加热方法中,马铃薯经蒸煮25min后的糊化效果最好.正交试验结果表明,奶粉含量和黄油含量对冷冻调理马铃薯饼的感官指标有高度显著的影响.对冷冻调理马铃薯饼的油脂的测试结果显示,未经油炸的马铃薯饼的脂肪含量为4.24%,而经过油炸后的马铃薯饼的脂肪含量为11.18%.经过一个月的冻藏后,未经油炸的冷冻调理马铃薯饼的油脂的过氧化值为1.94%,而经过油炸的冷冻调理马铃薯饼的油脂的过氧化值为7.79%.     

Comparison of the sensory profiles of regular and reduced-fat commercial processed cheese spreads

The sensory character of 16 samples of commercial, processed cheese spread has been characterized. Samples were selected to provide information on variations both between brands and, for products differing in fat content, within brands. Products were rated for eight flavour attributes and six textural attributes by a panel of 13 professional assessors. Significant differences in both the flavour and the texture of the spreads were associated with brand. No systematic differences were found between the flavour attributes and the fat content of the spread. However, differences were revealed between spreads – classified on the basis of fat content as regular, light and ultra light – in the sensory dimensions associated with texture and mouth feel. Nevertheless, within some brands the effect of reducing fat content was minimal. This result was probably achieved by other changes in product formulation.