Abstract: Raw pineapples were selected to obtain high-quality preserved pineapple. In this experiment, pineapples with different maturity levels in Xishuangbanna were used as raw materials. After identifying the maturity level of pineapples based on appearance, color, aroma and fruit hardness, sensory evaluation was conducted, while indicators such as water, sugar, acid, and protein were measured. Then, correlation analysis between raw pineapples and preserved pineapple fruit was conducted, and the quality of preserved pineapple was evaluated based on the key indicators and sensory evaluation of raw pineapples. The results showed that pineapple maturity was graded into light ripe, medium ripe, and full ripe according to taste, color, aroma and flesh hardness. In the sensory evaluation system of fresh pineapple fruit, the four indicators of color, taste, aroma and flesh hardness of medium ripe pineapples were all the highest, and their comprehensive scores were also higher than those of both light ripe and full ripe pineapples. Therefore, it was ultimately determined that fresh medium ripe pineapple fruit was the most suitable material for preserved fruit. When analyzing the indicators of mid ripening pineapples in different sampling periods, it was found that 1) the sugar content of pineapples fluctuated greatly during different sampling periods, and climate conditions had a certain impact on pineapple fruit; 2) the acid content first increases, then decreases, before finally slightly increasing during the ripening process of pineapples; 3) the moisture content is closely related to the weather conditions during the sampling period; and 4) the protein content increases with the accumulation of nutrients during the extension of the sampling period. From the correlation between raw pineapples and preserved pineapple, it can be seen that the sugar, acid and protein content of raw pineapples will have an impact on the quality of preserved pineapple, which to some extent determines its quality. The sugar, acid, moisture and protein of raw pineapples are closely related to the quality of preserved pineapple fruit. Therefore, the quality of preserved pineapple fruit can be predicted based on the relevant indicators of raw pineapples, and suitable raw materials for producing preserved pineapple fruit can be selected to provide a basis for producing high-quality preserved pineapple fruit, so as to further improve its comprehensive quality.

Key words: preserved pineapple, process improvement, raw material selection