Study On Fruit Appearance And Fresh Food Quality Characteristics Of 20 Apple Varieties(Lines)

Apple is one of the most important fruit trees in the world and China,and plays an important role in China’s fruit industry.In recent years,due to its special geographical and climatic conditions,the apple industry has flourished in the cold and high-altitude areas of southwest China,and the apple industry has been increasingly valued.At present,there is still a single variety in China’s apple industry.It is of great significance to carry out apple quality evaluation and selection of high-quality varieties under the special climatic conditions in the high-altitude apple production areas in the southwest to highlight apple characteristics and support the high-quality development of the industry.At the same time,it is very necessary to carry out apple breeding.The experiment was carried out in the laboratory of Guizhou Institute of Fruit Science,and 20 different varieties of apple fruits from Weining,Guizhou Province were randomly picked as the research object to carry out quality characteristics research.The investigation and research were mainly carried out from the aspects of sensory evaluation,conventional quality evaluation,determination of sugar and acid components and determination of aroma components.The results are as follows:1.From the results of sensory evaluation,we can see that most of the evaluators will first choose the fruit with smooth appearance,uniform color,bright color and moderate flavor when selecting apples.Crispy and juicy fruits with moderate acidity and sweetness are favored by most evaluators.At the same time,we found that each evaluator’s evaluation criteria for different varieties were relatively stable,some of them paid much attention to the appearance of fruit,while others paid more attention to the aroma of fruit.2.The single fruit weight of 20 apple varieties（lines）ranged from139.68 to 352.50 g,of which the single fruit weight of North19-147 was the largest and that of 16-112 was the smallest;In the measurement of fruit diameter,the longitudinal diameter and transverse diameter of North19-147 are the largest,the longitudinal diameter of 16-112 is the smallest,and the transverse diameter of North 15-98 is the smallest;According to the analysis of the fruit shape index of the sample,the index range is 0.80～0.97,the Qincui fruit shape index is the smallest,and the North1-4 is the largest;In the hardness measurement,Yanfu8 has the largest peeling hardness;The results of fruit color difference showed that the L*value was 34.62～90.34,with the maximum of 16-112 and the minimum of 22-40.2-14 and North19-147 are typical large-fruit apple resources.North1-4,North 15-98 and Qinmi fruit shape index are above0.95,which can be used as excellent parent resources to improve the size and shape of apple fruit.3.After the determination of the sugar and acid components of the test samples,the following conclusions were obtained:in the test apple samples,the total soluble sugar content in the fruit ranged from 70.70 to35.84 mg?g^-1,with an average of 112.73 mg?g^-1,and a coefficient of variation of 11.18%.The total acid content of the fruits of 20 apple varieties（lines）ranged from 2.60 to 7.92 mg?g^-1,with an average of 3.96mg?g^-1.The principal component analysis method was used to carry out factor analysis on the main indicators that constitute the evaluation of apple sugar and acid.Four indicators,including total soluble sugar,sweetness value,malic acid and ratio of malic acid to sweet acid,were selected for cluster analysis by k-means method.The 20 apple varieties（series）could be divided into 4 categories.4.In 20 apple pulp samples,30 volatile substances were identified,including 12 esters,accounting for 40%of the identified volatile substances,3 aldehydes,3 alcohols,2 ketones,2 alkenes and 8 other volatile substances.Among them,North19-147 pulp has the most volatile components,followed by Honey Crisp,29 volatile components were detected,and 2-14 and 92 pulp have the least volatile components.The three apple varieties（lines）of Micui,North19-147 and Meiwei can be used as excellent parents for breeding fruit varieties with rich aroma.This paper analyzes the quality of 20 kinds of apple samples collected from the high-altitude apple production areas in the southwest,and provides a reference basis for the selection of suitable apple varieties,optimization of variety structure and apple breeding in the project area by combining sensory evaluation with objective detection.