DEFECTS AND PEELABILITY OF PROCESSING TOMATOES

Peeling is one of the first operations in the manufacture of whole peeled and diced tomatoes, and the peelability of processing tomatoes is significantly affected by the presence of various tomato defects, in particular yellow eye and blossom‐end rot. Tomato maturity also impacts both the percentage of peeled fruit and yield. Immature fruits are typically undercolored and small in size. Sunburned regions on the tomato surface are difficult to peel as well. In this study, we determined the impact of 24 selected tomato defects on tomato peelability and yield of whole peeled tomatoes. There are potential advantages to sorting to remove selected tomato defects early in the process.     

PEELABILITY AND YIELD OF PROCESSING TOMATOES BY STEAM OR LYE

Approximately 25% of the processed tomatoes grown in California are made into value‐added foods such as whole peeled and diced tomatoes. Peel removal is the first step in this process, and it must be optimized for both quality and yield. The effect of peeling conditions on tomato cultivars Halley 3155 and Heinz 8892 (H 8892) was evaluated. Considerable texture loss results from peeling; however, firmness was greater for cv. Halley 3155 than for cv. H 8892 regardless of peeling conditions utilized. Peeling under low steam pressures (12 psig) was insufficient to adequately peel either cultivar. While high pressure steam (18 psig) was more efficient at peel removal, increasing vacuum level from 20 in. to 24 in. did not improve peelability of either cultivar. Because cultivar affected peelability and yield, specific tomato cultivars should be evaluated and directed to either paste or whole peeled and diced tomatoes as appropriate.     

有机溶剂浸提番茄红素的工艺优化

采用有机溶剂浸提法从番茄中提取番茄红素.先确定研究的因素,再采用单因素试验确定试验因素的最好条件,最后采用L9(34)正交试验,确定提取的最佳溶剂及最佳工艺条件.在单因素试验中得到皂化温度、乙醇处理时的料液比和二氯甲烷振荡提取时间的各因素的最佳条件,而在正交试验中得到提取番茄在皂化温度、乙醇处理时的料液比和二氯甲烷振苏提取时间的最佳工艺条件:皂化温度为50℃;乙醇处理时料液比为1∶3;二氯甲烷振荡提取时间为35 min.     

EVALUATION OF PROCESSING TOMATOES FROM TWO CONSECUTIVE GROWING SEASONS: QUALITY ATTRIBUTES, PEELABILITY AND YIELD

Peelability is an important quality parameter in the selection of tomato cultivars (cvs.) for whole peeled and dice processing. Six processing tomato cvs. were evaluated in two consecutive years to examine the effects of cv., maturity and physical attributes on peelability and yield. Physical attributes of the raw tomatoes (size, weight, pericarp wall thickness, color) and processed paste quality (pH, titratable acidity, soluble solids, Bostwick consistency, serum viscosity, color) were determined. Large variations in physical attributes and paste quality were observed in selected tomato cvs. and maturities. In general, most of the attributes indicative of paste quality were more desirable at the less mature (e.g., pink) stage and declined with maturity. Statistical analysis suggests that there were significant differences in percentage of peeled tomatoes, peel index, and yields of whole peeled and diced tomatoes between two consecutive growing years.     

PREPARATION OF HOP EXTRACTS WITHOUT USING ORGANIC SOLVENTS

Extraction of hops with liquid carbon dioxide at ambient temperature provides an attractive means of producing hop extracts which are rich in α-acids and free from hard resins, polyphenols, pigments and residual organic solvents. The resulting yellow extracts give beer with a clean bitter flavour when they are added during wort boiling. Manufacturing costs using the process are likely to be substantially less than in a conventional hop extraction plant.     

QUALITY CHANGES IN ORGANIC TOMATOES PACKAGED IN BIODEGRADABLE PLASTIC FILMS

Quality changes in organic tomatoes stored in four biodegradable packages and in LDPE‐bags at 11 ± 1C and 75–85% RH were studied for three weeks. Organic tomatoes were packed in perforated LDPE‐bags and the following biodegradable packages: a perforated Mater‐Bi®‐bag, a Biopol®‐coated paperboard tray overwrapped with a perforated Mater‐Bi®‐bag, a polylactide coated paperboard tray overwrapped with a perforated Mater‐Bi®‐bag, and a perforated cellophane bag. The tomatoes were analyzed for weight loss, moisture content, color, firmness and flavor. Package type had no significant influence on the tomatoes' sensory quality, whereas storage time significantly (p < 0.05) influenced the fruits' color, flavor and firmness. The tomatoes' firmness decreased, their redness (a*value) increased and their flavor diminished during storage. The tomatoes lost more of their weight in biodegradable packages than in LDPE packages.     

顶空气相色谱法测定三氯蔗糖中有机溶剂残留量

建立了三氯蔗糖中有机溶剂残留量的顶空气相色谱分析方法。采用大口径HP-快速GC残留溶剂柱为分离柱，FID为检测器，外标法进行定量。并对顶空平衡温度、平衡时间对残留有机溶剂测定的影响进行了分析研究。结果表明：甲醇在1．58mg／L-158．30mg／L乙醇在7．98mg／L～798、00mg／L内有良好的线性关系，相关系数分别为0.9997、0．9996；方法精套度试验RSD（n=6）分别为2．14％、1．83％；加标平均回收率（n=5）甲醇为99、72％、RSD=2．05％，乙醇为97．21％、RSD=2．51％；最低检测限分别为0．3mg，L、0．08mg，L。本方法快速、灵敏、准确、无污染。     

值得深思和借鉴的台湾纺织业

中国台湾纺织行业在国际经济低迷．市场竞争激烈的态势下，仍能保持较好的业绩，其成功的经验，确实值得我们深思和借鉴。     

肉类嫩化技术研究

改善肉类嫩度和减少各种肉类嫩度变化的措施己引起人们的日益关注，在许多国家这些措施已经被有效的应用于肉类工业。综述了肉类尸僵、成熟、嫩化机理、电刺激、钙处理、外源酶处理、机械嫩化、pH处理、高压处理、冲击波处理等影响肉类嫩度与品质的因素及嫩化的技术理论和方法。     

提高聚酯切片干燥效果的几点措施

介绍了提高聚酯切片干燥效果的几点措施.通过对BM干燥除湿系统的改进,由原来氯化锂转轮除湿,改为分子筛除湿,并对分子筛的再生温度及再生时间、预结晶的加热温度、主干燥的加热温度等工艺参数进行探讨,确定了聚酯切片干燥的最佳工艺参数.