| Green pepper is the main consumed vegetable in China. The objective of my work is to provide basic data and scientific suitability analysis of fresh-cut and cooking processing for green pepper cultivars in China, and also provide technical support for the choice of cooking methods and delivery time during Chinese catering distribution service. The suitability for fresh-cut and cooking process of main cultivars was analyzed. Considering the rapid development of Chinese food distribution industry in recent years, changes of sensory and nutrition quality in green peppers affected by different cooking methods as well as refrigerated and warm simulated delivery were investigated. Concrete conclusion summarized as followed: 1. For basic data acquisition and analysis, 20 green capsicum cultivars and 11 sweet green pepper cultivars were collected and planted. Fruits were picked at the same level of maturity; seventeen physical and chemical indexes were measured. Significant difference of each index among cultivars and correlation between the 17 indexes of all 31 cultivars were analyzed. Results showed that indexes varied from cultivars excepted for water content, and indexes which had a higher coefficient of variation were Vc content, beta carotene content and FRAP value. Results of correlation analysis showed that significant correlation was found among different indexes. 2. For fresh-cut processing, six representative indexes including sensory evaluation score, Vc content, product yield ratio, sugar to acid value, beta carotene content and total phenolics content were filtered as the main evaluation factors for green capsicum and five representative indexes including sensory evaluation score, Vc content, product yield ratio, sugar to acid value, beta carotene content for sweet green pepper were selected by principal component analysis, variable cluster analysis and factor assessment method. Weight of each representative index was determined by APH method. Grey correlation analysis was applied based on above results, and found that the best cultivars for fresh-cut processing were “Zhongjiao No.5 for sweet green pepper, “Guofu No.311”, “Zhong jiao No.106” for mild spicy green capsicums, “Longjiao No.6” for spicy green capsicums and “Xingshuzhoupila” for very spicy green capsicums. 3. For cooking processing, process for “Hupi–pepper” cuisine was chosen as cooking method. Sensory evaluation score, Vc content, total phenol content, and antioxidant ability were determined as main representative indexes considering the actual consumption. Based on the evaluation results of APH and grey correlation analysis, “Longjiao No.6” was the most suitable cultivar for “Hupi –pepper” cuisine among all the five commonly used cultivars including “Chang jian”, “Baofa No.1206”, “Zhongjiao No.106”, “Guofu No.208” and “Longjiao No.6”. 4. Pulp hardness was selected as cooking degree standard, and effects of traditional cooking methods including stir-frying, steaming, boiling and microwaving on the quality of green pepper were investigated. Results showed that all the four cooking methods could significantly decrease a* value, SSC and nitrite content, decrease Vc content by 15.0%-23.7%. On the contrary, cooking could significantly increase total phenolics content and antioxidant activity. But the effects of 4 cooking methods on the quality of green peppers were significantly different. The decrease order of a* values was microwaving > boiling > steaming > stir-frying. No significant difference was observed on Vc content among four cooking methods. Increase order of total phenolics content was stir-frying > microwaving > boiling > steaming. Increase order of antioxidant ability was steaming, boiling > stir-frying > microwaving. A great decrease of SSC in green pepper cooked by boiling was found, but no significant difference of SSC was observed among green peppers samples cooked by the other three methods and the raw materials. Decrease order of nitrite content by four cooking methods was boiling > steaming, microwaving > stir-frying. In a word, steaming and microwaving treatment could keep the nutritional quality of green pepper better, and significantly reduce nitrite content. So steaming and microwaving treatment were recommended as the most suitable cooking treatments for green peppers. 5. Quality changes of green pepper cooked by the above mentioned four cooking methods in the course of simulated delivery at 4℃ for 24 h and 65 ℃ for 90 min were observed. Steaming and microwaving were suitable for cuisine with green pepper as main material because they could keep sensory and nutritional quality better. Sensory and nutritional quality of cooked green pepper kept decreasing with the extension of both refrigerated and warm delivery time, nitrite content of green pepper kept increasing with the extension of refrigerated delivery time. It was recommended that the refrigerated delivery time of cuisine with green pepper as the main material shouldn’t be more than 24 h and the warm delivery time shouldn’t be more than 45 min.In conclusion, we collected the basic nutrient and sensory data of main green pepper cultivars in China; developed suitability evaluation system of fresh-cut and cooking processing for green peppers. We selected pulp hardness as a standard of cooking degree, and observed the quality changes in green peppers as affected by different cooking methods and refrigerated and warm distribution process. The results gained in this study could be referenced for the processing application of green pepper in China. |
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