Langerak D I
Ann Nutr Aliment. 1978;32(2-3):569-86.
During storage, transport and sale of prepacked vegetables, their quality deteriorates very quickly by microbiological decay, discolouration and desiccation. The experiments described were carried out with endive (Chichorium endiva L.) as a representative of the leaf vegetables. After processing (cutting, washing and drying), the product was packed in polythene bags without and with 4 perforations of 2 mm diameter. The endive was irradiated with 0 and 100 krad gammarays and afterwards stored at 10 degrees C, thus simulating the transport and sale temperature. The quality was studied on the basis of the following parameters. The gas composition in the bags, the microbiological composition, the Vitamin C (Ascorbic acid + Dehydroascorbic acid) content and the sensory quality. The experiments showed that the modified gas composition in the non-perforated bags, caused by the respiratory activity of the cut product, improved the quality. The low O2 and high CO2 content prevented discolouration, retarded the senescence and diminished the Vitamin C losses. The initial Total Viable Count of endive was 10(6) to 10(7) and the number of Enterobacteriaceae amounted to approx. 10(5) g-1 product, and increased in a couple of days to 10(8) and 10(7) g-1 respectively, resulting in decay of the product. The contamination with aerobic and anaerobic spores was low, viz. 10(1) to 10(2) g-1 and did not increase at 10 degrees C. An irradiation treatment of 100 krad reduced the Total Viable Count and the Enterobacteriaceae with 3-4 decimals, by which the shelf life increased with about 100% and almost all the Enterobacteriaceae were eliminated, so that the hygienic quality was improved. In prepacked endive nearly half of the Total Vitamin C content was lost within two days. The retention was strongly affected by the presence or absence of perforations; the effect of an irradiation treatment was slight.
在预包装蔬菜的储存、运输和销售过程中，其品质会因微生物腐烂、变色和干燥而迅速恶化。所描述的实验以菊苣（Chichorium endiva L.）作为叶菜类的代表进行。加工（切割、清洗和干燥）后，产品被装入没有打孔和有4个直径为2毫米孔的聚乙烯袋中。菊苣分别接受0和100千拉德的伽马射线辐照，之后储存在10摄氏度下，以此模拟运输和销售温度。基于以下参数对品质进行研究：袋内气体成分、微生物组成、维生素C（抗坏血酸+脱氢抗坏血酸）含量和感官品质。实验表明，切割后的产品呼吸活动导致未打孔袋内气体成分改变，从而提高了品质。低氧和高二氧化碳含量可防止变色、延缓衰老并减少维生素C的损失。菊苣的初始总活菌数为10⁶至10⁷，肠杆菌科数量约为10⁵ g⁻¹产品，几天内分别增加到10⁸和10⁷ g⁻¹，导致产品腐烂。需氧和厌氧孢子的污染较低，即10¹至10² g⁻¹，在10摄氏度下没有增加。100千拉德的辐照处理使总活菌数和肠杆菌科数量减少3至4个数量级，保质期延长约100%，几乎所有肠杆菌科都被消除，卫生质量得到改善。在预包装菊苣中，两天内几乎一半的总维生素C含量会损失。维生素C的保留情况受是否打孔的强烈影响；辐照处理的影响较小。
