石榴籽油脂肪酸组成及应用研究

用气相色谱法分析石榴籽油的脂肪酸组成，检出了６种脂肪酸：石榴酸８６．０１％、亚油酸５．１４％、油酸３．８１％、棕榈酸２．９１％、硬脂酸１．５２％，亚麻酸０．６１％，与桐油的脂肪酸组成极其相似。石榴籽油属干性油，是涂料工业的好原料。对水果也有十分明显的保鲜作用。     

微波杀菌保鲜面包的技术研究

面包是当今社会人们所衷爱的方便食品之一,但其在室温下保鲜期通常只有3-4d。本实验以当天焙烤的新鲜面包片为原料,经适当的微波杀菌处理后分别置于室温、冷藏(0-4℃)条件下保藏,确定适宜的保鲜期。实验结果表明,微波杀菌面包在室温下保鲜期为12d,冷藏条件下保鲜期为20d;而未经微波杀菌处理的面包在冷藏条件下保鲜期只有12d,说明适宜的微波杀菌处理有利于延长面包的保鲜期。     

Pulsed Ultra High Pressure Treatments for Pasteurization of Pineapple Juice

Sinusoidal and step-pressure pulses were compared with static pressure treatments for the inactivation of Saccharomyces cerevisiae 2407-1a in pineapple juice. No inactivation was observed after 40–4,000 fast sinusoidal pulses (10 cycles/s) at 4–400 sec in the 235–270 MPa range. Static 270 MPa treatments at 40 and 400 sec resulted in 0.7 and 5.1 decimal reductions, respectively. Slower 0–270 MPa step pulses at 0.1 (10 pulses), 1 (100 pulses), and 2 (200 pulses) cycles/s with 100 sec total on-pressure time resulted in 3.3, 3.5, and 3.3 decimal reductions, respectively. A comparable static pressure treatment resulted in 2.5 decimal reductions. Changing the on-pressure/off-pressure time ratio (3:1, 3:3 and 1:3) showed that treatments with longer on-pressure time, e.g., 0.6 sec on-pressure and 0.2 sec off-pressure were significantly more effective showing nearly a 4 decimal reduction in 100 sec.     

低温羊肉火腿综合保鲜技术的研究

根据栅栏因子保鲜理论,采用多种栅栏因子科学合理的组合,对低温羊肉火腿进行了综合保鲜研究,结果表明:原料减菌化处理(醋酸2%、双乙酸钠3%、抗坏血酸2%、硫代硫酸钠2%、山梨酸钾1%) 保鲜剂(Nisin0.15%、山梨酸钾0.19%、双乙酸钠0.11%) 水浴热处理(85~90℃、30min杀菌2次,中间急速冷却)可使低温羊肉火腿在0~4℃贮存条件下,货架期达6个月之久;同等条件下,微波120s热处理(功率900W,中心温度90℃)的羊肉火腿货架期达到3~4个月。     

龙眼核精油对采后草莓的保鲜效果

本文以"红实美"草莓为实验材料,研究了不同浓度龙眼核精油浸泡处理对草莓采后低温保鲜(4℃)的效果。结果表明,龙眼核精油对草莓采后具有显著的保鲜作用,可有效降低草莓的腐烂指数,减缓草莓中可溶性固形物、总糖、维生素C、总黄酮和总酚的损失速度,提高了果实对DPPH和ABTS自由基的清除能力,维持了其抗氧化活性,其中以精油浓度160μg/m L处理组效果最好,除可滴定酸外,其余指标均显著优于其它处理组和对照组。     

室温下不同电商包装对荔枝保鲜效果的比较

生鲜果蔬的电商包装方式对其保鲜效果至关重要。因此该研究以荔枝“仙进奉”为试验材料,探究在室温（28~29 ℃）条件下,新型保鲜纸箱与普通泡沫箱包装荔枝的品质变化规律。结果表明,两种包装形式均可延缓可溶性固形物（TSS）、可滴定酸（TA）、可溶性蛋白质及维生素C含量的变化,果实风味、营养成分维持较好,抑制了果皮褐变多酚氧化酶（PPO）、过氧化物酶（POD）酶活性的增加,减少了丙二醛（MDA）在物流运输过程中的积累。综合表明,在0~2 d内新型纸箱包装的荔枝在TSS、TA、维生素C等指标与普通泡沫箱包装差异不大,其2 d时新型纸箱的TSS、TA、维生素C含量分别为18.15 °Brix、0.6%及7.61 mg/100 g。与普通泡沫箱相比（MDA含量为0.07 μmol/g）,新型保鲜纸箱MDA的含量极显著降低（0.04 μmol/g）,荔枝果皮脂膜损伤减少。因此,在荔枝的短期贮藏中新型保鲜纸箱可替代普通泡沫箱作为电商物流包装材料,即具保鲜功能又环保可利用。     

Combined effect of aqueous chlorine dioxide and modified atmosphere packaging on inhibiting Salmonella Typhimurium and Listeria monocytogenes in mungbean sprouts

This study was conducted to investigate the effect of chlorine dioxide (ClO2) combined with modified atmosphere packaging (MAP) on inhibiting total mesophilic microorganisms, Salmonella Typhimurium, and Listeria monocytogenes in mungbean sprouts during refrigerated storage. Mungbean sprouts were packaged using 4 different methods (air, vacuum, CO2 gas, and N2 gas) following treatment with water or 100 ppm ClO2 for 5 min and stored at 5 +/- 2 degrees C. The population of total mesophilic microorganisms in mungbean sprouts was about 8.4-log(10) CFU/g and this level was not significantly reduced by treatment with water or ClO2 (P > 0.05). However, when samples were packaged under vacuum, N2 gas, or CO2 gas following treatment with ClO2, the populations of total mesophilic microorganisms were significantly reduced during storage (P < 0.05). Levels of S. Typhimurium and L. monocytogenes in mungbean sprouts following inoculation were 4.6- and 5.6-log(10) CFU/g and treatment with water followed by different packaging conditions (air, vacuum, N2 gas, and CO2 gas) had no significant effect on population reduction (P > 0.05). However, treatment with ClO2 significantly reduced populations of S. Typhimurium and L. monocytogenes by 3.0- and 1.5-log CFU/g, respectively (P < 0.05), and these reduced cell levels were maintained or decreased in samples packaged under vacuum or in N2 or CO2 gas during storage. These results suggest that the combination of ClO2 treatment and MAP such as CO2 gas packaging may be useful for inhibiting microbial contamination and maintaining quality in mungbean sprouts during storage.     

茁霉多糖在温州蜜柑常温保鲜中的应用

采用１％，３％的茁霉多糖溶液以及以茁霉多糖为主的乳状液对温州蜜柑进行涂膜，并在常温下（６～１５℃，相对温度６８％～９０％）进行贮存。研究结果表明，经涂膜的柑桔失重率、烂果率大大低于未经涂膜的柑桔。用１％茁霉多糖溶液涂膜的柑桔在常温下贮存至第１４０天时，好果率为８５．９８％，比控制组提高了３１．９０％，有效地延长了柑桔的采后货架寿命     

啤酒保鲜的新技术——超高压

超高压能够有效杀灭食品中的霉菌、酵母菌、细菌.从超高压处理保持啤酒的微生物稳定性、提高啤酒风味稳定性两方面加以分析,论述了超高压灭菌优于传统的加热灭菌的特点,指出了超高压技术应用于啤酒保鲜中存在的问题,并展望了其未来的发展方向.     

Free radicals and antioxidants in food and in vivo: What they do and how they work

A wide variety of oxygen free radicals and other reactive oxygen species can be formed in the human body and in food systems. Transition metal ions accelerate free‐radical damage. Antioxidant defenses, both enzymic and nonenzymic, protect the body against oxidative damage, but they are not 100% efficient, and so free‐radical damage must be constantly repaired. Nonenzymatic antioxidants are frequently added to foods to prevent lipid peroxidation. Several lipid antioxidants can exert prooxidant effects toward other molecules under certain circumstances, and so antioxidants for food and therapeutic use must be characterized carefully. Methods of measuring oxidative damage and trapping free radicals in vivo are briefly discussed. Such methods are essential in checking proposals that increased intake of food‐derived antioxidants (such as antioxidant vitamins) would be beneficial to humans.