低温贮藏条件下胡萝卜品质变化的研究

化工与生物技术学院毕业论文

低温贮藏条件下胡萝卜品质变化的研究Study on Carrot Quality Change under the Condition of Low

Temperature Storage

吉林化工学院

Jilin Institute of Chemical Technology

摘要

胡萝卜是伞形科二年生草本植物，以呈肉质的根作蔬菜食用，且其肉质根富含多种营养素。本试验以胡萝卜作为研究对象，研究在低温和冷冻贮藏条件下其品质的变化规律，包括水分含量、总糖含量、果胶含量、纤维素含量、维生素C 含量的变化。该研究对胡萝卜保鲜贮藏的方法具有指导意义，用于实际食品生产过程中优质原料的采集，尽可能降低采后损失，避免运销过程中的大量腐烂，保证消费市场的正常供应需求，指导食品加工生产，更好的为生产服务。试验材料购买后立即运回实验室，先随机抽取三根检测其各项品质指标的含量，其余试样预处理后三根一组装入自封袋中，每个自封袋用牙签扎18-20个通气孔，然后标号后分别置于冰箱的冷藏室和冷冻室贮藏贮藏量均为18根。贮藏期设为28d，每隔7d，对两种贮藏温度下的胡萝卜均取三根样品（即一个自封袋）进行各项指标的测定，每个指标测定3次，取平均值。结果表明，4℃条件下对胡萝卜的低温贮藏可以减缓胡萝卜的失水率、Vc损失率、果胶损失率以及粗纤维的增长率，而-20℃的冷冻贮藏条件则能减缓胡萝卜还原糖损失率。总之，4℃的的低温贮藏条件能有效地维持胡萝卜的品质。

关键词：胡萝卜；贮藏；低温；冷冻；品质

Abstract

The carrot is a umbelliferae biennial herb with fleshy roots of various nutrients which can be eaten as a vegetable. This experiment, taking the carrot as the research object, researches the change rule of water content, total sugar content, pectin content, cellulose content, and vitamin C content in state of low temperature and frozen storage. The research has guiding significance for the method of carrot storage, which can be used to collect high quality raw materials in actual food production process, to reduce postharvest loss as far as possible to avoid a lot of rot in marketing process, to ensure the normal supply demand for the consumer market ,and to guide food processing production, in a word, to offer better service for production. Take test materials back to the lab immediately after the purchase. Firstly, choose three roots to detect the content of each quality index. After the pretreatment of the other samples, put each three of them as a group into several valve bags. Use a toothpick to make 18-20 punctures on each valve bag as spiracles. Label them and storages 18 roots into the cold closet and another 18 roots into the freezing chamber of the refrigerator.

The storage period is set to be 28d. Every 7D, take out three carrot root samples (i.e.

a zip lock bag) from each storage temperature to detect the content of each quality index. Each index was measured for 3 times, and took the average value. The results showed that low temperature storage at 4 ℃ can slow down the loss rate of water , loss rate of Vc, loss rate pectin and the growth rate of crude fiber of the carrots , while frozen storage at -20 ℃ can slow down the carrot reducing sugar loss rate. In short, low temperature storage at 4 ℃ can effectively maintain the quality of the carrot.

Keywords: carrots; storage; temperature; freezing; quality

目录

摘要 ························································································································I Abstract ················································································································· II 第1章前言 ···································································································· - 1 -

1.1选题目的和意义 ················································································ - 1 -

1.2国内外研究现状 ················································································ - 1 -

1.2.1胡萝卜贮藏保鲜研究现状 ····················································· - 1 -

1.3目前果蔬的冷藏和预处理技术 ························································ - 5 -

第2章材料与方法 ························································································ - 6 -

2.1试验样品的选择 ················································································ - 6 -

2.2试验方案 ···························································································· - 6 -

2.3品质分析方法 ···················································································· - 6 -

2.3.1品质指标 ················································································· - 6 -

2.3..2试验仪器和试剂 ···································································· - 7 -

2.3.3试验方法 ················································································· - 7 -第3章结果与分析 ······················································································ - 13 -

3.1不同贮藏条件下水分含量的变化分析 ·········································· - 13 -

3.2 不同贮藏条件下还原糖含量变化分析 ········································· - 14 -

3.3不同贮藏条件下粗纤维含量变化分析 ·········································· - 15 -

3.4 不同贮藏条件下维生素C含量变化分析 ···································· - 16 -

3.5不同贮藏条件下果胶含量变化分析 ·············································· - 18 -

第4章结论 ·································································································· - 21 -参考文献 ········································································································ - 22 -致谢 ················································································································ - 25 -