Journal of Integrative Agriculture ›› 2018, Vol. 17 ›› Issue (05): 994-1002.DOI: 10.1016/S2095-3119(17)61795-7

• 论文 • 上一篇    下一篇

  

  • 收稿日期:2017-04-07 出版日期:2018-05-20 发布日期:2018-05-04

Evaluation indices of sour flavor for apple fruit and grading standards

YAN Zhen1*, ZHENG Li-jing1, 2*, NIE Ji-yun1, LI Zhi-xia1, CHENG Yang1    

  1. 1 Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture/Institute of Pomology, Chinese Academy of Agricultural Sciences, Xingcheng 125100, P.R.China
    2 Beijing Agriculture Technology Extension Station, Beijing 100029, P.R.China
  • Received:2017-04-07 Online:2018-05-20 Published:2018-05-04
  • Contact: Correspondence NIE Ji-yun, Tel: +86-429-3598178, E-mail: jiyunnie@163.com
  • About author:YAN Zhen, E-mail: yanzhen01@caas.cn; * These authors contributed equally to this study.
  • Supported by:

    This work was financially supported by the earmarked fund for the China Agriculture Research System (CARS-27), the National Program for Quality and Safety Risk Assessment of Agricultural Products of China (GJFP2017003) and the Scientific and Technological Innovation Project of the Chinese Academy of Agricultural Sciences (CAAS-ASTIP) .

Abstract: In order to establish grading standards of evaluation indices for sour flavor of apples, 10 indices of samples from 106 apple cultivars were tested, including: malic acid (Mal), oxalic acid (Oxa), citric acid (Cit), lactic acid (Lac), succinic acid (Suc), fumaric acid (Fum), total organic acids (ToA, the sum of the six organic acids tested), titratable acid (TiA), acidity value (AcV), and pH value.  For most of the cultivars studied (85.8%), the order of the organic acid contents in apples was Mal>Oxa>Cit>Lac>Suc>Fum.  Mal was the dominant organic acid, on average, accounting for 94.5% of ToA.  Among the 10 indices, the dispersion of pH value was the smallest with a coefficient of variation of only 8.2%, while the coefficients of variation of the other nine indices were larger, ranging between 31 and 66%.  There were significant linear relationships between Mal and two indices (ToA and AcV) as well as between ToA and AcV.  There were significant logarithmic relationships between pH value and four indices: Mal, TiA, ToA, and AcV.  All the equations had very high fitting accuracy and can be used to accurately predict related indices.  According to this study, Mal, ToA, and AcV of apple were normally distributed, TiA was close to normally distributed, whereas pH value had a skewed distribution.  Using the fitted normal distribution curves, the grading standards of Mal, TiA, ToA, and AcV were established.  The grading node values of pH value were obtained using the logarithmic relationship between pH value and Mal.  The grading standards of these five indices can be used to evaluate the sour flavor of apple.  This study provides a scientific basis for evaluating apple flavor and selecting apple cultivars.

Key words: apple ,  organic acid ,  sour flavor ,  evaluation indices ,  grading standard