果蔬貯藏保鮮概論：第四章 果蔬的低溫傷害及其它生理傷害(第2,3節(jié))

1、第四章 果蔬采后低溫傷害及其它生理傷害第二節(jié) 凍 害 Freezing injury 一、果蔬的冰點 Freezing point二、果蔬的凍結過程 緩慢凍結；速凍冰晶生成曲線水的結晶冰晶形成開始結晶同質：由最低溫度點開始結晶異質：由溶質開始結晶冰晶成長冰晶數目不變冰晶大小改變-1.5凍害二、防止凍害方法1、避免產品貯藏、運輸溫度低于冰點 2、產品受凍后應注意 緩慢解凍凍結期間避免搬動第三節(jié) 采后不適宜氣體引起的傷害長時間的無氧呼吸對果實有哪些傷害？CH3COCOOH CH3CHO + CO2CH3CHO +2NADH +H+ C2H5OH +2NAD+代謝不完全，能量釋放少使中間產物減少，影

2、響果蔬的其他代謝過程乙醛、乙醇對果蔬組織的毒害作用果蔬組織褐變、黑變產生酒精味、醛異味衰老斑果柄干枯第四節(jié) 采前不適宜條件引起的傷害一、苦痘病 Apple bitter pit癥狀：初期果皮上有褐色小斑，斑下果肉開始褐變，病斑多環(huán)繞在果實萼端之后果面出現褐色凹陷圓斑，病斑顏色加深，斑下果肉壞死干縮呈海綿狀，深 23mm病斑常以皮孔為中心，直徑35mm，以后可擴大至 1cm機理：缺鈣，氮鈣比失調防治：采前噴施硝酸鈣或采后浸鈣病因：氮、鈣比例失調，氮/鈣10-30二、蘋果水心病 Watercore癥狀：病部果肉出現水晶狀，質地較堅硬且呈半透明狀，半透明區(qū)域有的呈輻射狀，有的呈區(qū)域化分布，病變部位果

3、肉較甜，同時略帶酒味。機理山梨糖醇積累，以及鈣、氮不平衡病因：鈣氮不平衡，山梨醇積累NMR TechnologyBlock Watercore Radial Watercore三、營養(yǎng)素失衡黃冠梨雞爪?。ㄌ状筲}素營養(yǎng)失衡）四、蘋果日灼病 Apple sun scald第五節(jié) 病原菌侵染引起的病害一、果實主要病害 Disease果 實病 害致病菌柑橘類柑橘類仁果類茄果類槳果類瓜 類香蕉、芒果核果類甜瓜綠霉病青霉病青霉病黑斑病灰霉病炭疽病炭疽病軟腐病褐腐病粉霉病指狀青霉（Penicillium digitatum）意大利青霉（Penicillium italicum）擴展青霉（Penicilli

4、um expansum）互隔交鏈格（Alternaria alternata）灰葡萄孢（Botrytis cinerea）葫蘆科刺盤孢（Colletotrichum sp.)盤長孢狀刺盤孢（Colletotrichum sp.)匍枝根霉（Rhizopus stolonifer）果生鏈核盤菌（Monilinia fruticola)粉紅單端孢（Trichothecium roseum）（一）采前侵染病害（潛伏侵染）采前侵入采后發(fā)病，可從花期到采收前發(fā)生侵染侵染途徑：直接侵入、自然孔口、傷口侵入Prusky et al., 2013二、病原菌侵染 InfectionSusceptibility o

5、f strawberry fruits to Colletotrichum acutatum artificial infection during ripening. (Guidarelli et al., 2011)Golden Smoothee apples inoculated with Penicillium digitatum. A visible reaction around the inoculation site was found in immature apples (A). P. digitatum was able to infect a small group o

6、f apples from commercial harvest (B) but was not able to develop decay. P. digitatum was able to infect and develop rot on apples from over-mature harvest reaching a complete apple rot at 10 d after inoculation (C). Vilanova et al., Postharvest Biology and Technology 88 (2014) 5460Scanning electron

7、microscopy of Botrytis cinerea on tomato fruit at sampling times. (I) The development of B. cinerea on tomato fruit in the inoculated control. Sampling times were (A) 3 HPI, (B) 6 HPI, (C) 12 HPI, HPI, (D) 24 HPI, (E), 48 HPI and (F) 72 HPI. (G) 96 HPI, (H) 120 HPI. Q. Li et al. / Biological Control 61 (2012) 113120（二）采后侵染病害孢子萌發(fā)芽管伸長附著胞形成侵染絲穿透侵入（三）采后侵染方式：直接穿透果皮上角質層侵入通過果皮上皮孔、氣孔等部位侵入通過傷口侵入潛伏病原菌侵染活性恢復二次侵染農業(yè)生產措施與病害防治加強 樹、土、肥、水、藥等管理，生產優(yōu)質果病害發(fā)作、流行 病害越冬 的控制采前潛伏侵染的控制規(guī)范采收，采后及時預冷和貯藏保鮮采后殺菌劑處理戴挫霉、撲海因、特克多、咪鮮