天然食用玉米黄色素的研究

由玉米淀粉厂的副产品──黄蛋白粉提制的食用玉米黄色素是一种油溶性色素。提取率６％左右，最大吸收峰４４６ｎｍ左右，稀溶液呈柠檬黄色。本色素的１％溶液对太阳光较敏感，但在４０℃下较稳定。在低温下或添加到固体食品中稳定性很好。它安全、无毒。而且是β－胡罗卜素类物质，对调节人体代谢有积极作用。该色素可用于人造奶油、糖果、糕点等方面的食品着色。     

从番茄提取番茄红素与β-胡萝卜素的工艺研究

研究从番茄中提取、分离番茄红素与β-胡萝卜素的工艺技术。结果表明：在丙酮、石油醚、正己烷、乙酸乙酯4种溶剂中,丙酮对β-胡萝卜素和番茄红素的提取率最高。丙酮提取的次数以3次较为适宜。用中性氧化铝柱色谱,依次用石油醚与氯仿洗脱,可分离β-胡萝卜素与番茄红素。丙酮提取番茄类胡萝卜素的适宜工艺条件为：温度60℃、时间4h、pH值5、料液比1：5。     

Pasta products made from sweetpotato fortified with soy protein

Sweetpotato flour (Beauregard cultivar) was treated with sodium hydroxide solution and then fortified with defatted soy flour (DSF) or soy protein concentrate (SPC) at levels of 0, 15, 30, and 45 g/100 g. Pasta made from 100 g/100 g alkaline-treated sweetpotato flour (ASPF) had the lowest cooking loss (9.9 g/100 g) with the highest firmness (1.8 N). Cooking loss increased as levels of DSF and SPC increased (from 9.9 to 16.6 g/100 g). Addition of DSF and SPC increased the lightness (“L*” value) from 40.6 to 48.7, and decreased the redness (“a*” value) from 21.6 to 15.2. Substitution of DSF and SPC decreased firmness from 1.8 to 0.4 N, cohesiveness from 0.6 to 0.5 and springiness from 1.2 to 1.1 mm. Pasta made from 100% ASPF had highest β-carotene content (9.0 mg/100 g). The β-carotene contents decreased from 7.9 to 2.7 mg/100 g as the levels of DSF and SPC increased.     

锁掷酵母与海洋红酵母的营养成分分析

研究了锁掷酵母与海洋红酵母中的类胡萝卜素,氨基酸、脂肪酸组成。锁掷酵母与海洋红酵母中的总类胡萝卜素含量分别为21.42 mg/L,8.02 mg/L。锁掷酵母中含有较多的β-胡萝卜素,而海洋红酵母中以红酵母烯为主。锁掷酵母中含有的β-胡萝卜素以全反式结构为主,全反式结构占总β-胡萝卜素的60%左右,顺式结构主要有13-顺和9-顺β-胡萝卜素。锁掷酵母和海洋红酵母中的蛋白质中均含有常见的20种氨基酸,不饱和脂肪酸占总脂肪酸的比例分别为74%和76%。文中对锁掷酵母与海洋红酵母中含有的类胡萝卜素、蛋白质和脂肪酸进行了比较分析,为锁掷酵母在饲料行业的深入应用奠定了基础。     

牦牛肉及脂肪中β-胡萝卜素含量测定

以牦牛肉及牦牛脂肪为原料,利用氨水-乙醇溶液进行皂化,石油醚作为萃取剂,采用单因素试验确定最佳皂化条件,并利用正交试验分析了料液比、萃取温度、萃取时间3个因素对β-胡萝卜素提取效果的影响。结果表明:牦牛脂肪的最佳皂化条件为40℃、1 h,最佳萃取条件为料液比为1∶15(g/m L)、萃取温度为50℃、萃取时间为2 h,在该条件下牦牛脂肪中β-胡萝卜素含量的预测值为30.53mg/100g,试验验证值为30.60mg/100g;牦牛肉中β-胡萝卜素的最佳萃取条件为料液比为1∶15,萃取温度为60℃,萃取时间为1 h,在该条件下牦牛肉中β-胡萝卜素含量的测定值为5.61 mg/100 g,试验验证值为5.70 mg/100 g。     

Simultaneous HPLC quantification of total cholesterol,tocopherols and β-carotene in Barrosã-PDO veal

A simple, rapid and sensitive procedure for the simultaneous determination of total cholesterol, tocopherols and β-carotene in meat is described. The method involves a direct saponification of the meat, a single n-hexane extraction and the analysis of the extracted compounds by normal-phase HPLC, using fluorescence (tocopherols) and UV–Vis photodiode array (cholesterol and β-carotene) detections in tandem. Rates of recovery of spiked meat samples were 93% for cholesterol, 83–86% for (α-, β- and -γ) tocopherols and 89% for β-carotene. Repeatabilities were high (CV < 6%) for all determined compounds, except for δ-tocopherol. This tocopherol, which is not usually present in meat, showed a much lower recovery percentage (73%) and repeatability (12.8%). This methodology was applied for the quantification of total cholesterol, tocopherols and β-carotene in three muscles (longissimus thoracis, longissimus lumborum and semitendinosus) of the Portuguese traditional Barrosã-PDO veal, obtained from autochthonous calves fed extensively during summer (with the least abundant green pastures) and slaughtered in early autumn (October). Barrosã-PDO veal showed median contents of total cholesterol (0.50–0.56 mg/g) and, depending on the analysed muscle, moderate to high contents of α-tocopherol (3.3–3.9 μg/g) and β-carotene (0.07–0.09 μg/g), suggesting an high sensorial and hygienic quality.     

利用超临界CO2技术萃取红酵母β-胡萝卜素的初步研究水

本研究初步尝试了利用超临界CO2萃取技术从红酵母中提取β－胡萝卜素的效果。结果表明,红酵母经酸-热法破壁后,在所确定的最适萃取条件下（萃取压力30MPa、温度40℃、CO2流量20Kg／h、萃取时间90min）,β－胡萝卜素萃取率可达0．83％。这说明,利用超临界CO2苹取红酵母β－胡萝卜素有一定的可行性,但萃取率较低,对影响萃取的各种因素有待今后深入探讨。     

Carotene Degradation and Isomerization during Thermal Processing: A Review on the Kinetic Aspects

Kinetic models are important tools for process design and optimization to balance desired and undesired reactions taking place in complex food systems during food processing and preservation. This review covers the state of the art on kinetic models available to describe heat-induced conversion of carotenoids, in particular lycopene and β-carotene. First, relevant properties of these carotenoids are discussed. Second, some general aspects of kinetic modeling are introduced, including both empirical single-response modeling and mechanism-based multi-response modeling. The merits of multi-response modeling to simultaneously describe carotene degradation and isomerization are demonstrated. The future challenge in this research field lies in the extension of the current multi-response models to better approach the real reaction pathway and in the integration of kinetic models with mass transfer models in case of reaction in multi-phase food systems.     

β-胡萝卜素纳米粒特性研究进展

β-胡萝卜素纳米粒化克服了β-胡萝卜素低水溶性的缺点,扩大了β-胡萝卜素在食品领域的应用范围。近些年来国内外关于β-胡萝卜素纳米粒的研究逐渐深入,关于其理化性质和代谢特性的研究取得了很多成果。本文从这两个方面介绍β-胡萝卜素纳米粒的研究方法与进展。     

Inhibition of oxidation in 10% oil-in-water emulsions by β-carotene with α- and γ-tocopherols

The effects of low concentrations of β-carotene, α-, and γ-tocopherol were evaluated on autoxidation of 10% oil-in-water emulsions of rapeseed oil triacylglycerols. At concentrations of 0.45, 2, and 20 μg/g, β-carotene was a prooxidant, based on the formation of lipid hydroperoxides, hexanal, or 2-heptenal. In this emulsion, 1.5, 3, and 30 μg/g of γ-tocopherol, as well as 1.5 μg/g of α-tocopherol, acted as antioxidants and inhibited both the formation and decomposition of lipid hydroperoxides. Moreover, at a level of 1.5 μg/g, γ-tocopherol was more effective as an antioxidant than α-tocopherol. At levels of 0.5 μg/g, both α- and γ-tocopherol significantly inhibited the formation of hexanal but not the formation of lipid hydroperoxides. Oxidation was effectively retarded by combinations of 2 μg/g β-carotene and 1.5 μg/g γ- or α-tocopherol. The combination of β-carotene and α-tocopherol was significantly better in retarding oxidation than α-tocopherol alone. While γ-tocopherol was an effective antioxidant, a synergistic effect between β-carotene and γ-tocopherol could not be shown. The results indicate that there is a need to protect β-carotene from oxidative destruction by employing antioxidants, such as α- and γ-tocopherol, should β-carotene be used in fat emulsions.