山核桃仁碱法脱涩工艺研究

为探索一种利用NaHCO₃对山核桃仁脱涩的碱法脱涩工艺,基于综合了脱涩率与感官评分的响应值,通过单因素试验和响应面试验优化其工艺参数,并对比碱法脱涩与传统的沸水脱涩对山核桃仁游离酚、结合酚含量,以及过氧化值、碘值、酸价等指标的影响。结果显示:优化后的碱法脱涩工艺参数为脱涩温度65 ℃,脱涩时间100 min,NaHCO₃质量分数5%,固液比(g·mL^-1)1∶15。在此条件下,山核桃仁的脱涩率为92.04%,感官评分为9.2分,响应值为75.47。与沸水脱涩相比,碱法脱涩既能去除苦涩味,又能更大限度地保留山核桃仁中的结合酚,减少油脂、脂肪酸和不饱和脂肪酸的氧化,从而更好地保持山核桃仁的品质。

Study on alkaline deastringency of hickory kernel

In order to explore a suitable alkaline deastringency method for hickory kernel, based on the response value (consisting of both deastringency rate and sensory score), single-factor tests and response surface test were adopted to optimize its technical parameters. Besides, the effects of both the proposed alkaline deastringency method and the traditional boiling-water deastringency method on the contents of free phenol and bound phenol, peroxide value, acid value and iodine value were explored. It was shown that the optimized technical parameters were as follows: deastrinency temperature of 65 ℃, deastrinency time of 100 min, NaHCO₃ mass fraction of 5%, solid-liquid ratio (g·mL^-1) of 1∶15. Under this condition, the deastringency rate was 92.04%, sensory score was 9.2, and the response value was 75.47. Compared with the traditional boiling-water deastringency method, the proposed alkaline deastringency method could remove astringency from hickory kernel, retain more bound phenol, reduce the oxidization of fat, fatty acid and unsaturated fatty acid, and maintain the quality of hickory kernel.