本研究以柚子砂囊形变程度为参数，考察了不同机械挤压程度对沙田柚、白肉蜜柚和红肉蜜柚砂囊物理破损程度、营养成分、色泽及柚皮苷、柠檬苦素等苦味物质的影响。结果表明，机械挤压对柚子砂囊的色泽、总酸含量影响不大。随着机械挤压程度的增加，3个柚子品种砂囊的汁液流失率、可溶性蛋白含量、柚皮苷含量、总酚含量、可溶性固形物含量上升，抗坏血酸含量、原果胶含量均下降，可溶性果胶和脂肪含量在机械损伤致形变程度为40%时达到最大值。与白肉蜜柚和红肉蜜柚相比，机械损伤导致沙田砂囊总糖含量下降2.89%，柠檬苦素含量增加64.12%；柚皮苷含量增幅较大，增幅为17.48%。本研究表明，机械挤压越大对柚子砂囊损伤越大，而引起的苦味物质累积则因柚子品种而异，其中机械损伤引起沙田柚苦味的增加较为明显。

In this study, the deformation degree of the pomelo juice sac was used as a parameter to investigate the effects of different degrees of mechanical extrusion on the physical damage on Shatian pomelo, white flesh pomelo and red flesh pomelo, as well as their nutritional composition, color, and bitter substances including naringin and limonin. The results showed that mechanical extrusion had little effect on the color and total acid content of the three types of pomelo juice sacs. With the increase of the degree of mechanical compression, the juice loss rate, soluble protein content, naringin content, total phenol content, and total soluble solid content of the three types of pomelo samples increased, whilst their ascorbic acid content and protopectin content decreased. The soluble pectin content and fat content reached their maximum when the degree of deformation caused by mechanical damage was 40%. Compared with the white flesh pomelo and red flesh pomelo, mechanical damage decreased the total sugar content by 2.89%, increased limonin content by 64.12% in Shatian juice sacs, with a greater increment of naringin content (by 17.48%). This study indicated that the greater compression the mechanical extrusion, the greater the damage to the pomelo juice sacs. The accumulation of bitter substances varied depending on pomelo varieties, with the increase of the bitter taste in Shatian pomelo juice sacs being greater.

广东省特色农机装备技术研发专项（粤农计[2018]52号）；广东省农业技术体系创新团队项目（2019KJ108）；广东省农业科学院果蔬加工研究团队项目（201604TD）