CAN WE PREDICT PEELING PERFORMANCE OF PROCESSING TOMATOES?

Tomato processors are increasingly interested in being able to predict whether tomatoes will peel well, and therefore, yield high‐value processed tomatoes. We describe two statistical models for peeling applied to multiple years of data. One model is appropriate for perfect or defect‐free tomatoes, and the second model is valid for the normal population of tomatoes obtained following mechanical harvesting. The ability to peel perfect tomatoes was significantly affected by exposure of tomatoes to temperatures greater than 100F, by fruit weight and by pericarp wall thickness. The peelability of a normal population of tomatoes was influenced by tomato weight and width as well as degree‐days and exposure to temperatures greater than 90F. Thickness of the pericarp walls and red layer positively affected the peelability of normal tomatoes. The ability to predict tomato peelability using statistical models may improve the quality of processed tomatoes and may result in more efficient commercial peeling operations.     

FREEZE PEELING IMPROVES QUALITY OF TOMATOES

SUMMARY— A process of peeling tomatoes using low temperature-short time freezing was perfected. Liquid nitrogen (BP-196°C was used as the refrigerant for freezing the skin and only a thin layer of cells just beneath the skin. The fruit was immediately thawed, after which the skin was quickly and easily removed from the fruit. Liquid nitrogen-peeled samples were evaluated for loss of peel and trim, as well as lycopene and carotene in the peeling process and these losses compared with samples peeled in boiling water. The losses in peel and trim were reduced by approximately 50%, and significantly less lycopene was lost by nitrogen peeling. The peel and trim of fall tomatoes had a greater amount of lycopene and carotene than spring tomatoes. The nitrogen-peeled samples were canned without additives, with sodium chloride and with calcium chloride added and compared with samples peeled with boiling water. There was a decrease in the percentage of broken fruit in the canned tomatoes peeled by liquid nitrogen. Titratable acidity and °Brix were higher and pH was lower in these samples. Color of the homogenized canned product was not statistically different; however, the nitrogen-peeled tomatoes had a better visual color. The calcium chloride added-nitrogen-peeled samples possessed a higher degree of firmness than the comparably treated boiling-water-peeled samples, indicating that the nitrogen-peeled tomatoes utilized the added calcium to a greater extent in firming.     

PROCESSING OF FOXTAIL MILLET FOR IMPROVED NUTRIENT AVAILABILITY

Foxtail millet grains were soaked in distilled water (1:5, w/v) for 12 h at room temperature, dehulled; dehulled and soaked; and dehulled, soaked and cooked in distilled water (1:3, w/v), and the effects of removal of polyphenols and phytate on the in vitro protein digestibility (IVPD) and availability of iron and zinc were measured. The results showed that polyphenols and phytate were decreased significantly up to 50.92 and 49.89%, respectively. The IVPD, however, increased up to 38.71%. The iron and zinc contents decreased up to 18.79 and 18.61%, respectively, but the ionizable iron and zinc were increased up to 55.45 and 80.18%, respectively. This indicated the suitability of simple processing techniques for improvement of availability of nutrients from foxtail millet.     

芹菜汁醋酸保健饮料的生产工艺

以芹菜为原料,经酒精发酵、醋酸发酵制成芹菜醋,再加入芹菜汁、蜂蜜、白砂糖调配成芹菜汁醋酸保健饮料．最佳调配比例为芹菜醋25％、芹菜汁25％、蜂蜜6％、白砂糖3％。酒精发酵最适宜pH值为3．5,当酒精度达8％时停止发酵,醋酸发酵产酸量达6．1％时停止发酵。     

澳洲青苹加工品质的测定

测定了高酸品种澳洲青苹的固形物、有机酸和引起果汁褐变的主要成份——多酚类物质(以绿原酸计)，固形物含量比其他品种苹果的平均含量高1．51个百分点，有机酸含量高于其它苹果0．122个百分点，而绿原酸仅为61．82mg／L，远远低于普通苹果(秦冠)的绿原酸含量258．57mg／L。实验表明，澳洲青苹是目前最适合加工浓缩果汁的品种之一。     

低糖树莓果脯生产工艺的研究

以红树莓或速冻树莓为原料,对影响树莓果脯的烫漂、硬化、护色、渗糖、浸糖、干燥等关键工艺技术进行研究.试验表明:最佳烫漂时间为2min,温度为85℃;护色剂采用1%的柠檬酸,时间20min～30min:用0.1%的氯化钙和0.2%的亚硫酸氢钠的混合溶液浸泡4 h;糖液配置用50%的淀粉糖浆、0.5%的果胶、0.15%的柠檬酸:真空度在0.085 MPa,维持真空时间20 min、充气时间为60min;常温浸糖4 h;在70℃下干燥4 h.整形后再干燥4 h;为最佳生产工艺条件.     

POTASSIUM HYDROXIDE REPLACEMENT FOR LYE (SODIUM HYDROXIDE) IN TOMATO PEELING

Lye (sodium hydroxide [NaOH]) peeling is the most common method for peeling tomatoes in the Midwest U.S. With the rise in the cost of NaOH and the associated disposal problems, alternative methods for peeling need to be examined. Solutions of NaOH, potassium hydoxide (KOH) and calcium hydroxide (Ca[OH] ₂ ) at different concentrations were compared to determine their efficacy as peeling agents. Ca(OH) ₂ was ineffective as a peeling agent because of its low solubility. KOH produced peeling equivalent to NaOH, but at half the normality. A lower normality is needed because of the increased reactivity of KOH compared to NaOH. This is further demonstrated by the addition of salts to the solution. The use of KOH instead of NaOH may result in cost savings and decreased waste disposal problems.     

为CGPSS－F仿真运行选择汉字系统

叙述了为ＣＧＰＳＳ－Ｆ选择汉字系统的方法，以便能使ＣＧＰＳＳ－Ｆ仿真系统在内存容量为６４０ＫＢ的微型机上顺利运行。对于内存小的微机使用汉字有一定的参考意义。     

去皮工艺对菠萝浓缩汁颜色变化的影响

就去皮工艺对菠萝浓缩汁品质的影响及产品在贮藏过程中的褐变情况进行分析研究.结果表明去皮工艺对菠萝浓缩汁的褐变指数、叶绿素、原花青素、总酚、抗坏血酸、HMF等指标有显著差异;通过吸附脱色可以减少这种差异,从而使菠萝果肉浓缩汁和经过吸附脱色的带皮榨汁的全果浓缩汁在加工后的外观颜色以及品质方面没有显著差异.但随储藏时间的延长和储藏温度的升高,经过吸附脱色的全果浓缩汁的非酶褐变情况明显比菠萝果肉浓缩汁加重,二者在贮藏期内非酶褐变的活化能分别为71.45 kJ/mol和63.02 kJ/mol.在贮藏过程中采用冷藏手段,带皮加工并经吸附脱色的菠萝全果浓缩汁完全可以达到菠萝果肉浓缩汁的质量水平.