中英文文献
附录1相关英文文献
Research which maintains freshness about the Chinese litchi strawberry
China as early as had the litchi strawberry in the Ming Dynasty to maintain freshness the method, its procedure was, chose the great bamboo, opened the crack, put in the litchi strawberry to seal again. Afterward used the litchi strawberry hangs into the well water to carry on the short-term to store. At present, the Chinese litchi strawberry stores maintains freshness is mainly uses the chemical agent to soak the method which the fruit and the low temperature transportation unifies: The litchi strawberry fresh fruit with maintains freshness the chemical agent dip, the packing, then low temperature transportation. In addition, other litchi stawberry maintain freshness the method also to have many, induces mainly has the following several kinds:
⑴The froth box adds the ice. The litchi strawberry mature period is centralized, also does not bear the storage and transportation extremely. At present the developed country uses generally Leng Lian transports in our country also with difficulty popularly, therefore the recent years litchi strawberry production area started to use one kind of froth box to add the ice the litchi strawberry storage and transportation maintaining freshness technology, generally after 3 day and nights transportation, the litchi strawberry still maintained original bright red, the flavor is invariable, the good result rate reached above 93%, the moisture loss did not surpass 3%. The material has the froth box, the ice piece, the old cotton fiber, the big water jar, the round bamboo basket as well as the sealing compound generally and so on. Selects the tattered fruit, the turning brown fruit and the disease-carrying insect fruit and so on, and carries on the suitable reorganization and the trim to the cob; Uses the clear water and the broken ice piece modulation water temperature first for 4-8℃, joins the benzene to match the density especially for the volume fraction suitable preservative liquid, packs with the bamboo basket chooses the good litchi strawberry fresh fruit to soak 4-5 minutes in the preservative liquid, puts out drainings 10-15 minutes. The supplement solution and the ice piece, maintain frequently the liquor strength and the water temperature; Puts an ice bottle on froth box's opposite angle each vertical stroke, will draining the dry fresh litchi strawberry to put in the froth box, the most top plate good box lid, seals with the sealing compound; When transportation, fronts old cotton
fiber in the compartment base. The froth box and the compartment broadside parallel compact arrangement, the manhole faces on, then all around and the box goes against in the compartment fills in the shop old cotton fiber. The entire process request operation is careful, the quick-moving, handles with care, from picks the fruit to complete to the load request in 4-6 hours.
⑵Air regulation storage maintains freshness the law. Uses changes the storage place the gaseous component, under the specific relative low temperature, reduces the oxygen content suitably and enhances the carbon dioxide content the air environment, suppresses the litchi strawberry fruit respiration and reduces the enzyme activeness, achieves stores maintains freshness the effect. The findings indicated that in the storage temperature 3-5℃, the relative humidity 90%, the storage place carbon dioxide volume fraction is 3%, the oxygen volume fraction is under 5% conditions, “the glutinous rice fried ricecake”, “Huai” and so on variety litchi chinenses after when stores 30d, its first-level and the second-level fruit's good result rate reaches as high as 92%, but the different variety, slightly has the difference to the storage place carbon dioxide and the oxygen density request. What should pay attention, carbon dioxide density Gao Hui has had the physiological injury to the fruit, when its volume fraction reaches 8%, the fruit pulp has the slight unusual smell production, when surpasses 10%, not only the turning brown fruit are many, moreover the quality fruit has the strong wine taste. And the turning brown aggravation is because the high carbon dioxide had destroyed the tonoplast, causes in the vacuole the phenol material overflow and the enzyme contact, intensified the enzyme to press the turning brown; The high carbon dioxide causes the cell death, the polyhydric phenol spontaneous oxidation turning brown.
In recent years, some people used the fast sufficient nitrogen law to carry on the litchi strawberry to store. The first litchi strawberry seal in the big account, pulls out with the vacuum pump the big account the vacuum, again is connected the nitrogen cylinder and the big account, enters the nitrogen sufficiently to the account. Because in stores in the process to need the regular extraction partial gas to carry on the ingredient examination, will lose the few gas, after will therefore each time examine, should supplement the few nitrogen to the account. After storing 40d, the good result rate is 70%, the flavor was still good, but control group's sample in 13d time already lost the goods value. Entire stores the process sugar drop is 2%-4%, stores the period
Vc content to drop to 22-26mg/100g by 33-37mg/100g.
⑶The chemical agent maintains freshness the law. Its basic principle is the drugs role in the litchi strawberry, plays the anticorrosion, the sterilization. Some can form one kind of not obvious transparent membrane rapidly in the litchi strawberry surface, seals up the fruit blowhole effectively, thus reduces the breath intensity, delays the fruit to be senile. May use the medicine has executes Bulgaria and, Turk many as well as some domestically produced fruit antistaling agent.
⑷Cryogenic storage maintains freshness the law. Its principle is depends upon the low temperature the function, suppresses the microorganism the reproduction, and slows down the fruit the respiration. Litchi strawberry cryogenic storage maintains freshness contract 30d, the fruit outward appearance is fresh, the flavor is normal, but under after its storehouse's normal temperature the shelf life is shorter than without the refrigeration fresh fruit, thus for transports far sells in distant markets brings the major difficulty. Its low temperature request 10℃ below (3-5℃ good), relative humidity 90%-95%, and temperature, humidity relative stabilization, not suitable changeable or sudden change. But passes through this way preservation the litchi strawberry, once enters the normal temperature environment, the turning brown speed is often quicker.
⑸Quick-freeze stores maintains freshness the law. One of litchi strawberry turning brown primary factors is the litchi strawberry peel existence oxidation catechol polyphenoloxidase, the temperature is lower, its activeness is weaker. The quick-freeze process should maintain at - 23℃ to - 196℃; The storage temperature should in - 18℃ below, the relative humidity be 90%. Work and so on packing should carry on - 5℃ the low temperature environment. The litchi strawberry quick-freeze stores maintains freshness the time to be possible to reach above 1a. But after passes through defrosting, the husk change turning brown, loses the original attractive natural luster, the flavor also misses, the dehiscent fruit rate is high. In order to reduce the dehiscent fruit rate, may to 0℃ freeze again before the freeze the fruit precooling. Regarding the husk turning brown, uses generally boils sets the hair floats -> the citric acid -> table salt to protect the color law control.
Stores maintains freshness the existence question
China the litchi strawberry stored the maintaining freshness technology to have the big enhancement in recent years, but still had many problems. If before recovering,
manages extensively, does not have the strict plant disease regulatory measures, the natural prematurely dropped fruit are many, and some fruits are often invaded in the vegetal period by plant disease dye, after does not favor the recovery, stores maintains freshness; When recovery and storage and transportation, because the recovery time and the operation do not work as well as the packing is bad, easy to cause the fruit mechanically, the artificial damage; The litchi strawberry most planters in the outlying mountainous area, investment environment's limit, the habitat are lacked the precooling to process the facility, storage capability are insufficient; At present, the Chinese litchi strawberry stored the research which maintained freshness many still to occupy the experimental stage, has not made the important breakthrough; Stores the maintaining freshness technology difficulty with to promote and so on. China not yet establishes the science reasonable circulation management system, the litchi strawberry fruits market distribution is mainly depending on the individual commerce, is impossible to have plans carries on the market the possible arrangement, all these direct or the indirect influence litchi strawberry has stored the maintaining freshness technology the promotion and the application.
The litchi strawberry maintains freshness development direction and countermeasure
In view of the fact that China's economic development level as well as the litchi strawberry habitat's condition and the environment, the litchi strawberry will maintain freshness from now on should maintain freshness the direction to the normal temperature to develop, it will maintain freshness the essence will be must maintain the fruit cell at the normal temperature temporary lodging in the bright condition, if cell after the fruit will pick very quick death, will then be unable to realize maintains freshness. Therefore suggested that about the litchi strawberry mature first two weeks, should utilize natural or carries on by the natural material synthesis antistaling agent to it spurts executes processing, causes to maintain freshness the ingredient to enter the litchi strawberry and to accumulate gradually. Maintains freshness the ingredient to be possible to reduce the physiological activity intensity in the litchi strawberry in vivo existence, to slow down moisture content disappearing, to reduce pH effectively the fluctuation and suppresses the harmful microorganism to grow, thus the extension litchi strawberry maintains freshness the time under the normal temperature condition; The injury which should through reduces the litchi strawberry to litchi strawberry's
pathology research and the prevention before picking receives, to maintain freshness finishes the preparation; According to formerly experienced, the litchi strawberry against turning brown and anti-germ's ability is very big along with the variety different difference, therefore, should strengthen the fine litchi strawberry variety screening research which from now on enantiopathia bears stores, and carries on the disease-resistant insectproof gene through the bio-engineering technology to implant the research, enhances the fruit the keeping quality; Should establish the perfect litchi strawberry the synthesis to maintain freshness the system, namely from the litchi strawberry seedling selective breeding, the planter technology, the cultivation management, picks the technology and so on various aspects to carry on the overall evaluation, to the litchi strawberry recovery around the question which prevents disease, the anticorrosion, the graduation, the pretreatment, storing, the transportation, the sale and so on possibly to appear does further studies, guaranteed that each link can reduce to litchi strawberry's harm the bottom.
Should speed up the establishment to conform to the international market request standard and the disposal procedure, the extension fresh fruit supply time, the strengthened commodity competitive spirit, enhances the fruits the packing level, further develops the domestic and foreign latent markets, meets the current litchi strawberry industry rapid development need; The development litchi strawberry fresh fruit processing and the development use's research, displays the litchi strawberry recovery after fully economic efficiency and social efficiency. Should develop early to the litchi strawberry fresh fruit processing and the development use research, particularly the litchi strawberry fruit pulp extraction process and equipment's research, by about face tradition backward process technology, develops the market absorption capacity to be big, the technology content high processed products, the promotion litchi strawberry processed products day by day standardization, the superior electron particle materialization and the diversification, satisfy the domestic and foreign markets particularly the export market the demand; The establishment litchi strawberry profession Production association, further consummates its circulation system. Reduced raw material waste, energy consumption and to land occupancy maximum limit, promotion litchi strawberry industry development.
附录2英文文献中文译文
关于中国草莓保鲜的研究
中国早在明朝就有了草莓保鲜方法,其做法是,选择巨竹,开隙,放入草莓再密封。后来又采用把草莓吊入井水之中进行短期贮藏。目前,中国草莓贮藏保鲜主要是采用化学药剂浸果和低温运输相结合的方法:草莓鲜果用保鲜化学药剂浸洗、包装,然后低温运输。除此之外,其它的草莓保鲜方法还有很多,归纳起来主要有如下几种:
⑴泡沫箱加冰。草莓成熟期较集中,又极不耐贮运。目前发达国家普遍采用的冷链运输在我国还难以普及,因此近年来草莓产区开始采用一种泡沫箱加冰的草莓贮运保鲜技术,一般经3昼夜运输后,草莓仍保持原来的鲜红色,风味不变,好果率达93%以上,水分损失不超过3%。材料一般有泡沫箱、冰块、旧棉絮、大水缸、圆竹筐以及封口胶等。选出破烂果、褐变果和病虫果等,并对果穗进行适当整理及修剪;先用清水及碎冰块调制水温为4-8℃,加入苯来特配成浓度为体积分数适当的防腐液,用竹筐装满选好的草莓鲜果在防腐液中浸泡4-5分钟,拿出沥10-15分钟。经常补充药液和冰块,以保持药液浓度及水温;在泡沫箱的对角各竖放一个冰瓶,将沥干的鲜草莓放入泡沫箱内,最后盖好箱盖,用封口胶密封;运输时,在车厢底部垫一层旧棉絮。将泡沫箱与车厢长边平行紧凑排列,盖口朝上,然后在车厢四周及箱顶填铺旧棉絮。整个过程要求操作仔细,动作迅速,轻拿轻放,从采果至装车要求在4-6小时内完成。
⑵气调贮藏保鲜法。采用改变贮藏库的气体成分,在特定的相对低温下,适当降低氧气含量和提高二氧化碳含量的空气环境,抑制草莓果实呼吸作用并降低酶的活性,以达到贮藏保鲜效果。研究结果表明,在贮藏温度3-5℃,相对湿度90%,贮藏库的二氧化碳体积分数为3%,氧气体积分数为5%的条件下,“糯米糍”、“淮枝”等品种的草莓经贮藏30d 时,其一级和二级果的好果率高达92%,但不同品种,对贮藏库的二氧化碳和氧气浓度要求略有差异。应该注意的是,二氧化碳浓度过高会对果实产生生理伤害,当其体积分数达8%时,果肉有轻微异味产生,超过10%时,不但褐变果多,而且好坏果都有浓烈酒味。其中褐变加重是因为过高的二氧化碳破坏了液泡膜, 使液泡内的酚类物质外溢与酶接触,加剧了酶促褐变;高二氧化碳使细胞死亡,多元酚自发氧化褐变。
近年来,有人采用快速充氮法进行草莓贮藏。首先把草莓密封在大帐中,用真空泵将大帐抽成真空,再将氮气瓶与大帐相连,向帐内充入氮气。由于在贮藏过程中需要定期抽取部分气体进行成分检测,会损失少量气体,所以每次检测后,应向帐内补充少量氮气。贮藏40d 后,好果率为70%,风味尚佳,而对照组的样
品在第13d 时已经丧失商品价值。整个贮藏过程糖度下降为2%-4%,贮藏期间Vc 含量由33-37mg/100g降至22-26mg/100g。
⑶化学药剂保鲜法。其基本原理是药品作用于草莓,起到防腐、杀菌作用。有的则能在草莓表面迅速形成一种不可见的透明膜,有效封闭果实气孔,从而降低呼吸强度,延缓果实衰老。可使用的药物有施保克、特克多以及一些国产水果保鲜剂。
⑷低温贮藏保鲜法。其原理是依靠低温的作用,抑制微生物的繁殖,并减缓果实的呼吸作用。草莓低温贮藏保鲜期约30d ,果实外观新鲜,风味正常,但是其出库后的常温下货架寿命比未经冷藏的鲜果短,从而给远运远销带来较大的困难。其低温要求10℃以下(3-5℃较佳) ,相对湿度90%-95%,且温度、湿度相对稳定,不宜多变或骤变。但经此种方式保存的草莓一旦进入常温环境,往往褐变速率更快。
⑸速冻贮藏保鲜法。草莓褐变主要因素之一是草莓果皮存在氧化邻苯二酚的多酚氧化酶,温度越低,其活性越弱。速冻过程应保持在-23℃至-196℃;贮藏温度应在-18℃以下,相对湿度为90%。包装等工作应在-5℃低温环境中进行。草莓速冻贮藏保鲜期可达1a 以上。但经解冻后,果壳更易褐变,失去原有诱人的天然色泽,风味也差,裂果率高。为了降低裂果率,可在冻结前把果实预冷到0℃再冻结。对于果壳褐变,一般采用沸水烫漂→柠檬酸→食盐护色法控制。
贮藏保鲜存在问题
中国近年来草莓贮藏保鲜技术有较大的提高,但仍存在不少问题。如采收前管理粗放,没有严格的病虫害控制措施,自然落果多,且有些果实往往在生长期就被病虫害侵染,不利于采收后贮藏保鲜;采收和贮运时,由于采收时期和操作不当以及包装不善,容易导致果实机械、人为损伤;草莓多数种植在边远山区,受投资环境的限制,产地缺乏预冷处理设施,贮藏能力不足;目前,中国草莓贮藏保鲜的研究很多仍处在试验阶段,均未取得重大突破;贮藏保鲜技术难于推广等。中国尚未建立科学合理的流通管理体系,草莓果品市场流通主要是靠个体商贩,不可能有计划地进行市场的合理安排, 所有这些都直接或间接影响了草莓贮藏保鲜技术的推广与应用。
草莓保鲜的发展方向及对策
鉴于中国的经济发展水平以及草莓产地的条件与环境,今后草莓保鲜应该向常温保鲜方向发展,其保鲜的实质是要保持果实细胞在常温下处于鲜活的状态,若细胞在果实采摘后很快死亡,则无法实现保鲜。因此建议,在草莓成熟前两个星期左右,就应该运用天然或由天然物质合成的保鲜剂对其进行喷施处理,使保
鲜成分进入草莓并逐渐积累。保鲜成分在草莓体内的存在可有效降低生理活动强度、减缓水分散失、降低pH 的波动和抑制有害微生物生长,从而延长草莓在常温条件下的保鲜时间;应通过对草莓的病理研究与防治减轻草莓在采摘之前所受到的伤害,为保鲜作好准备;根据以往经验,草莓防褐变及抗病菌的能力随品种的不同差异很大,因此,今后应加强对抗病耐贮藏的优良草莓品种的筛选研究,并通过生物工程技术进行抗病防虫基因的植入研究,提高果实的耐贮性;应建立健全草莓的综合保鲜体系,即从草莓种苗选育、种植技术、栽培管理、采摘技术等各方面进行综合考虑,对草莓采收前后的防病、防腐、分级、预处理、贮存、运输、销售等可能出现的问题作进一步研究,确保每一环节都能将对草莓的损害降低到最低点。
应加快建立符合国际市场要求的标准和处理程序,延长鲜果供应期,强化商品竞争意识,提高果品的包装水平, 进一步开拓国内外潜在的市场,以适应当前草莓业迅猛发展的需要;开展草莓鲜果加工与开发利用的研究,充分发挥草莓采收后的经济效益和社会效益。应及早开展对草莓鲜果加工与开发利用的研究,尤其是草莓果肉提取工艺及其设备的研究,以彻底改变传统落后的加工技术,开拓市场容量大、科技含量高的加工产品,促进草莓加工产品日趋标准化、优质化和多样化,满足国内外市场尤其是出口市场的需求;建立草莓行业生产协会,进一步完善其流通体系。最大限度的减少原料的浪费、能源的消耗和对土地的占用,促进草莓产业的发展。