最新电大《园艺产品贮藏加工学》复习题.doc

园艺产品贮藏加工学考试题一、名词解释(每小题2分，共16分)1、呼吸速率与呼吸热采后园艺产品进行呼吸的过程中，消耗呼吸底物，一部分用于合成能量供组织生命活动 所用，另一部分则以热量的形式释放出来，这一部分热量称为。呼吸热会提高贮藏环境的温度，不利于贮藏保鲜。2、果实预冷是将刚采收的新鲜的园艺产品在运输、贮藏或加工以前迅速除去田间热，将其品温降低到适宜温度的过程。3、致病性与抗病性致病性是指病原菌对寄主组织的破坏和毒害的能力，也称为致病力或病菌毒性（1分）。植物对病菌进攻的抵抗的能力叫抗病性或忍耐力（1分）。4、果实冷害与冻害当果实受到0度以下的低温伤害时，细胞间隙形成冰晶体，原生质脱水。这种现象叫果实冻害。（1分）当果实受到冰点以上的低温伤害时，出现组织内部变黑和干缩，外表凹陷、出现斑点等，这种现象叫果实冷害。（1分）5、CA贮藏 CA指的是根据产品的需要和人的意愿调节贮藏环境中各气体成分的浓度并保持稳定的一种气调贮藏。常指降低氧气和提高二氧化碳的含量。6、Respiration climacteric指园艺产品在采后初期呼吸强度逐渐下降，而后迅速上升，并出现高峰，随后迅速下降的现象。7、结露现象是指在果蔬贮藏过程中，特别是用塑料薄膜袋或帐贮藏产品时，过多的水汽从空气中析出而在产品上凝结成水株的现象。养的 损失，除去颗粒表面的气体，防止装灌时固体物上浮，减少杀菌和装罐时起泡，减少金属罐内壁的腐蚀（1分）。8、均质与脱气均质：将果蔬汁通过均质小孔（孔径0.020.03mm），使果肉、果胶在高压下（1020兆帕）进一步破碎为大小均匀的粒子，减少颗粒和汁液间的密度差，保持制品均一浑浊的状态（1分）。脱气：脱除果汁中的氧气，防止变色和营养的 损失，除去颗粒表面的气体，防止装灌时固体物上浮，减少杀菌和装罐时起泡，减少金属罐内壁的腐蚀（1分）。二、问答题（共84分）1、为什么园艺产品贮藏保鲜中需把低温作为最基本最重要的条件？（10分）答：因为低温可以降低呼吸强度、减少乙烯的产生、减少水分的蒸发、减少病原物的感染、降低酶的活性，从而大大延长贮藏期，并保持果蔬的风味和品质。2、试举一例说明泡菜、果酱的加工过程（20分）答：泡菜（10分）(1) 准备发酵容器：可用泡菜坛、发酵罐，清洗干净并晾干。（1分）(2) 原料选择与处理：包括清洗和切分，大小以可以放进坛口为宜（2分）（3）配制泡菜盐水：食盐以精制盐为佳，浓度为6-8%。为了增进色、香、味，可加入黄酒2.5%，白酒0.5%，白砂糖1-2%，红辣椒1%，以及茴香、橙皮、胡椒、姜、蒜等浅色香料少许，并用纱布包扎成香料袋，盛入泡菜坛中。（3分）(4)泡制与管理:将菜料装入坛内,边装边压紧实，致一半时，放入香料包，再装菜料至离坛口6-8CM处，加入盐水淹没菜料。切忌菜料露出水面，接触空气而发生氧化变质。盐水注入至离坛口3-5CM。盖上坛盖，注满坛沿水，任其发酵。（2分）（5）取食：致发酵中期（4-5D）时，泡菜品质最佳，应及时取出包装，阻止其继续变酸。坛盐水以10%的盐水 为好，要注意经常更换，以防水干。发酵期中每天轻揭盖一次，防止坛盐水倒罐。在泡菜完熟、取食阶段，若出现长霉生花，可先将菌膜捞出，再缓缓加入酒精或白酒，或加入洋葱、生姜片等，密封几天后花膜会自然消失。取放泡菜要用清洁消毒的工具。（1分） （6）商品包装： 切分整形、配制汤汁、装袋（罐）、杀菌冷却。（1分）果酱的加工过程（以菠萝为例）：（10分）（1）原料选择及处理：选择含果胶和酸量多，芳香味浓，成熟度适宜的菠萝（8-9成熟）。首先剔除霉烂变质、病虫害严重的不合格果，清洗、去皮、去芽眼、切碎。（2分）（2）：打浆：用打浆机打成匀浆。（2分）（3）加热软化：锅中加水 ，水为果肉重的20%，再加糖，糖量为果实重的50%左右，煮沸。（2分）（4）调味：煮制约20分钟加适量的果胶、柠檬酸，使成品含酸量为0.5-1%，果胶量为0.4-0.9%。（1分）（5）加热浓缩：边加热边搅动，防止锅底焦化。直致可溶性固形物为60%以上。（2分）（6）装罐密封：趁也装瓶，贴上标签。（1分）3、果实切开（或去皮）后不久会变色？如何防止？（20分）答：原因：因为发生了酶促褐变反应，果实中的酚类物质在酶的作用和空气中氧的作用下生成醌，醌再转变成黑褐色物质。（5分）护色方法（1）漂烫护色：用沸水热烫1-2分钟（3分）（2）食盐溶液护色：用1-2%的食盐水。（3分）（3）亚硫酸盐溶液护色：0.1-0.3%的亚硫酸钠、亚硫酸氢钠和焦亚硫酸钠等浸泡3-5分钟。（3分）（4）有机酸溶液护色：檬酸、苹果酸或抗坏血酸，浓度为0.5-1.0%。（3分） (5) 抽空护色：干抽法和湿抽法（常用的抽空液有糖水、盐水、护色液三种）。（3分）4、为什么采收后的芒果使用了防腐保鲜剂它还会腐烂？（34分）答：因为果实的贮藏保鲜效果受到许多因素的影响：（1） 采前因素对贮藏保鲜的影响（内在因素）：A、不同种类与品种其贮藏性不同。B、生态因素中温度、光照、降雨、土壤、地理条件等因素都会影响贮藏效果：温度高、温差大、光照强、降雨充沛、土壤肥沃、地势高纬度适中果树生长好，其果实采收后耐贮。C、农业技术因素如施肥、灌溉、整形修剪、疏花疏果等对园艺产品 的生长发育、质量状况及贮藏性有显著影响。（8分）（2） 贮藏条件的影响：贮藏场所的温度、湿度、气体组成等直接影响到果实的贮藏寿命。如采用适宜的低温、适宜的高湿、降低氧气提高二氧化碳的含量等都可以延长贮藏寿命。（8分）（3） 采收成熟度：4分（4） 采后商品化处理技术：5分（5） 采用的贮藏方法：果蔬贮藏的方法很多，如采用常温贮藏、机械冷藏、气调贮藏、辐射保鲜、使用化学防腐保鲜剂、果实涂膜处理等均可以延长贮藏时间，提高保鲜效果。（8分） 总之，果蔬贮藏保鲜是一件非常复杂的系统工程，它不仅取决于果蔬所处的贮藏条件、贮藏环境及采用的贮藏方法、防腐剂的使用等，采收之前果实的生长状况、技术管理水平及环境因子等对采后的贮藏特性有非常重要的影响。如果芒果采收前就已经有了病原菌的潜伏侵染，采收后使用防腐剂以及采用先进的贮藏方法和适合的贮藏环境也没有效果，因此，必须从品种选择开始，加强栽培管理、防治病虫害并且采用合适的贮藏方法、创造适宜的贮藏环境才能取得最佳的贮藏效果。（3分）A boxer that only has front legs refuses to let his disability hold him back as he charges across a beach with his four-legged pals.一条只有两条前肢的拳师犬不愿让残疾成为前进的障碍，他同其他四条腿的伙伴们一同在海滩上尽情狂奔。In an adorable video showing his first trip to the beach, Duncan Lou Who can been seen excitedly galloping along the sand and paddling in the water.这段可爱的视频展现了名叫Duncan Lou Who的狗第一次来到海边的场景，他兴奋地在沙滩上飞奔、或是趟水嬉戏。His exciting day trip was filmed by Panda Paws Rescue, a Washington state-based charity that cares for Duncan and other dogs with special needs.这段视频由位于华盛顿州的慈善组织Panda Paws Rescue拍摄，该组织专门照料Duncan以及其他有特殊需求的狗。Despite only having front limbs, the boxer is able to not only balance, but also run really fast and play with the other dogs that joined him for the outing.虽然只有两条前肢，Duncan不仅能让自己保持平衡，还能快速奔跑，和其余同他一起远足的狗 狗玩耍。He was born with deformed back legs, which were later removed to make the dog more comfortable. Duncan出生时，它的后肢就是畸形的，此后为了让他舒服些,只能进行截肢。His owners, who posted the video on YouTube, said he has a wheelchair but doesn't like to use it.主人们将视频传到了YouTube上，他们说有一把供Duncan使用的轮椅，但是他并不爱用。'We let him be free and just walk on his two legs. There is some slow motion in this video, but none of the video has been sped up, this gives you an idea of how fast Duncan really it,' his owners said. “我们让他自由地用两条腿行走。视频中有些特意制作的慢镜头，但是没有任何一处做过加速处理，你们可以通过视频感受到Duncan跑得有多快。”主人们说。The thrill of running through the surf was clear to see, as Duncan raced people and dogs across the sand, with his tail wagging excitedly. Duncan踏着浪花，在沙滩上同其他人及狗赛跑，还兴奋地摇着尾巴，他的喜悦之情显而易见。Duncan's owners have described him as a 'trooper', adding on charity's Facebook page: 'He's happy, healthy and as far as he knows, normal too.'主人们用“骑兵”一词来形容Duncan，他们在组织的Facebook中写道：“他很快乐，也很健康；而且在他自己看来，他是条正常的狗。”'It would be the best if he had four legs, of course, but his body wasn't built to have back legs and that's OK. He and we have just adapted.' “他如果能有四条腿当然最好，但是他天生就失去了后肢，这也没什么关系，无论是他还是我们都已经适应了这一点。” I'm thankful to PSG for giving me the opportunity to continue but I feel now is the right time to finish my career, playing at the highest level. If you had told me as a young boy I would have played for and won trophies with my boyhood club Manchester United, proudly captained and played for my country over one hundred times and lined up for some of the biggest clubs in the world, I would have told you it was a fantasy. I'm fortunate to have realised those dreams.To this day, one of my proudest achievements is captaining my country. I knew every time I wore the Three Lions shirt, I was not only following in a long line of great players, I was also representing every fan that cared passionately about their country. I am honoured to represent England both on and off the pitch.I wouldn't have achieved what I have done today without my family. I'm grateful for my parents' sacrifice, which made me realise my dreams. I owe everything to Victoria and the kids, who have given me the inspiration and support to play at the highest level for such a long period. I also want to thank Simon Fuller and his team for their continued support. I want to thank all my team-mates, the great managers that I had the pleasure of learning from. I also want to thank the fans who have all supported me and given me the strength to succeed. Nothing will ever completely replace playing the game I love, however I feel like I'm starting a new adventure and I'm genuinely excited about what lies ahead. I'm fortunate to have been given many opportunities throughout my career and now I feel it's my time to give back.3