【作者】 赵悦平；

【导师】 张志华；

【作者基本信息】 河北农业大学 ， 果树学， 2004， 硕士

【摘要】 核桃坚果由硬壳和种仁组成，种仁营养丰富，深受人们喜爱，而硬壳则很少受到重视。本试验设计采用了专用测试系统，对核桃坚果硬壳结构进行全面系统的研究，探讨了硬壳与坚果品质之间的关系，旨在为正确评价核桃坚果质量提供科学方法，为核桃良种选育及栽培提供科学依据。主要研究结果如下： 1．核桃坚果硬壳结构(缝合线紧密度、机械强度、硬壳密度、硬壳厚度、硬壳细胞大小)与虫果率、污染率、裂果率等显著相关，缝合线紧密度越大，虫果率、污染率、裂果率越小，硬壳结构是核桃坚果重要性状之一。经分析认为：适宜的缝合线紧密度范围是130～370N。 2．首次提出径仁率的概念，通过对出仁率、单果重与径仁率进行相关分析表明，径仁率比出仁率更能形象地表示核桃坚果的饱满程度。 3．不同品种之间、普通核桃(Juglans regia L．)与铁核桃(Juglans sigillata Dode．)之间及同一品种不同产地的核桃坚果硬壳结构指标有显著差异，说明品种、气候、土壤等是影响核桃硬壳结构的关键因子。 4．核桃坚果缝合线紧密度随采收期的临近而下降，硬壳机械强度及密度随采收期的临近而上升，但硬壳密度在采前1周左右又呈下降趋势。 5．不同的油脂理化指标与硬壳结构指标有一定相关性，其中酸价与缝合线紧密度极显著负相关；丙二醛含量与硬壳细胞大小极显著正相关，与缝合线紧密度显著负相关。 6．核桃种仁颜色与硬壳结构(硬壳密度、硬壳厚度、缝合线紧密度、硬壳细胞大小、虫果率、污染率)、坚果品质(棕榈酸含量、硬脂酸含量、径仁率、出仁率)间相关性显著。 7．随着贮藏期延长，种仁酸败程度加重，冷藏条件下核桃种仁油脂的酸败程度明显低于室温贮藏。不同品种油脂理化指标及油脂中各脂肪酸含量差异较大，油脂理化指标与不饱和脂肪酸含量问存在明显的相关性，亚油酸含量高则碘价高，油脂更易氧化变质。 8．核桃坚果呼吸速率与坚果含水量密切相关，呼吸速率随着坚果失水及贮藏期的延长变小，不同品种的核桃坚果在采收后20天内呼吸速率差异较大，20天后(含水量稳定后)各品种呼吸速率基本一致，贮藏期间呼吸速率较低，变化较小。更多还原

【Abstract】 Walnut includes shell and kernel, the latter is popular because of abundant nutrition, but the former is not attached importance. The experiment carried the roundly systemic studies on the shell structures of walnut by designing and using the special apparatus; probed the correlations of the shell structures and nut qualities. The purpose was supplying a scientific means for correctly assessing the walnut quality, a scientific foundation for selecting improved cultivar and culturing of walnut. The main results were as follows:1. The shell structure indexes (shell seal grade, mechanical strength, density of shell, shell thickness and volume of shell cell) had obvious correlations with the rate of wormed nut, the stain rate and the rate of dissilient nut. The shell seal was tighter, the rate of wormed nut, the stain rate and the rate of dissilient nut were littler, and the shell structure was one of the important characters of walnut. The fitting range of shell seal grade was 130-370N.2. The experiment proposed kernel weight per centimeter for the first time, and thought that kernel weight per centimeter was more visual and exact than kernel ratio to show the full degree of walnut through the correlation analysises on kernel weight per centimeter with kernel ratio and per nut weight.3. The shell structure indexes had distinct difference among different cultivars, between ordinary walnut (Juglans regia L.) and Tie walnut (Juglans sigillata Dode.), among the same cultivars of different places of production. So the cultivar, climate, soil and so on were the key factors that affected walnut shell structures.4. With Hearing the harvest, the shell seal grade of walnut descended, the mechanical strength and density ascended, but the shell density descended in 1 week before harvest.5. Different fat physiology and biochemistry indexes correlated with the shell structures definitely, in which the acid value and MDA content had the notably negative correlation with the shell seal grade, the MDA content had the positive correlation markedly with volume of shell cell.6. There were obvious correlations between the kernel colour and shell structures (density of shell, shell thickness, shell seal grade, volume of shell cell, rate of wormed nut and stain rate), nut qualities (hexadecylic acid content, stearic acid content, kernel weight per centimeter, kernel ratio).7. The kernel became sour more and more badly along with the storage stage prolonging. The becoming sour of kernel fat ,in cold storage was lower obviously than in the room temperature storage. The fat physiology and biochemistry indexes and fatty acidcontents of different cultivars were all distinct. The fat physiology and biochemistry indexes obviously correlated with the unsaturated fatty acid contents. The linoleic acid content was high, iodine value was high, and the fat easily happened the oxygenation and deterioration.8. Rate of respiration of walnut closely correlated with the water content of nut, the rate of respiration was low more and more with nut losing water and storage stage prolonging, rates of respiration of different cultivars had biggish difference in 20 days after harvest; but 20 days later (after water contents not changing) the rates of respiration were accordant basically, and there were not obvious changes in the storage.更多还原