lesson4PrinciplesOfRefrigeratedGasStorageOfFoods

1、principles of refrigerated gas storage of foodsnthere are clear benefits from the cool temperature storage of foods. as this thesis evolved there was another development which paralleled it. nparalleled pr,leld adj. 并行的，平行的 n食品低温贮藏有明显的好处。以往，随着这一课题展开，就出现与之相平行的另外新的发展。 nwhile slow in maturing， it also

2、had significant potential. the area dealt with the gas storage of fresh foods.ndealt with:处理；涉及；做生意 n新的课题虽然尚处在缓慢成熟的过程中,却同样有很大的潜力。这一领域的研究内容是生鲜食品的气体保藏法。 nthe matter had appeared in quite an unexpected systemrefrigerated dough. in this lesson we will explore the nature and direction of the technology o

3、f gas storage as it is evolving.ndough du n. 生面团；金钱 n此事首先出现在一个完全没有意料到的食物体系冷藏生面团之中。本课我们将探讨当前在发展中的气体保藏技术的特点和趋势。gas packed refrigerated dough充气包装冷藏面团充气包装冷藏面团ncooking is the art of preparing foods by heating until they have changed in flavor， appearance， tenderness and chemical composition.ntenderness t

4、endnis n. 亲切；柔和;嫩度n烹任是利用加热方法使食物的风味、外观、嫩度和化学组成发生变化的食物制作技艺。 nbaking is a form of cooking that is carried out in an oven. baked bread is not only one of the most ancient foods manufactured by man， it is also the food most widely eaten in the world. n焙烤是一种在烤炉中进行的烹饪形式。烤制的面包不仅是人类制作的最古老食品之一，而且也是世界上食用最广泛的食品

5、。 nthe actual baking process is really the last and most important step in the production of bakery products. through the agency of heat， an unpalatable dough mass is transformed into a light， porous， easily digestible and appetizing product.nbakery beikri n. 面包店；烘焙食品 nunpalatable ,npltbl adj. 味道差的，

6、难吃的nporous p:rs, pu- adj. 多孔渗水的；能渗透的；有气孔的 nappetizing pitaizi adj. 开胃的；促进食欲的 nfreshly baked products can be produced and distributed effectively. however，the storage life of soft baked goods is generally less than a week.nduring this time， products stale and lost desirable tastes and textures. the a

7、ppealing aroma of baked goods is slowly lost after the products are removed from the ovens. for best eating， baked products are generally soon after baking.nstale steil vt. 使变旧；变得不新鲜 nan ingenious means of providing consumers with ready-to-bake dough products evolved in the past few decades. this pr

8、oduct line is called refrigerated dough.ningenious indi:njs adj. 有独创性的；精制的； nthe essential technology involves the preparation of a dough， packaging it in a sealed container capab1e of holding about 5 atm of gas， and causing an initial controlled release of carbon dioxide.ndioxide daiksaid n. 二氧化物 n

9、其基本的工艺包括面团的制备、面团包封在能够保持气体压力为5atm的密封容器中、以及co2最初有控制地促使释放。 nunder refrigerated conditions， slightly above freezing， such products can be effectively produced and distributed，and when baked yield excellent products.nmatz（1968） reported that in such commercial refrigerated dough practices，there is ordina

10、rily used， as the leavening agent or gas generating component， a slowly acting sodium acid pyrophosphate of the approximate formula na2h2p2o7 in combination with sodium bicarbonate.nleavening agent 膨松剂；变质剂 nsodium sudim n. 化学 钠 npyrophosphate ,pairufsfeit n. 无化 焦磷酸盐； 焦磷酸酯 nbicarbonate baik:bnit碳酸氢盐，

11、酸式碳酸盐 n马茨（1968年）曾报道，在这种商业化冷藏面团的生产作业中，通常使用一种作用缓慢、分子式大体为na2h2p2o7的焦磷酸氢钠与小苏打的混合物作为膨松剂（产气成分）。 nall ingredients are mixed under very rigidly controlled temperature conditions. （note： dough temperature out of mixer， 10 to 15）nrigidly rididli adv. 严格地；坚硬地；严厉地 n所有的配料要在非常严格控制的温度下混合（注：从混合器出来的面团温度在1015）。 nthe

12、resulting dough is rolled out and the dough is then sheeted and cut into banks， such as discs about 5 cm in diameter by l.2 cm thick. the cut-outs are dusted with rice flour or oiled to prevent sticking together.nrolled out 铺开；滚减 nsheet i:t n. 薄片，纸张；薄板；床单 vt. 覆盖；使成大片 adj. 片状的ndiameter daimit n. 直径 n

13、dust dst n. 灰尘；尘埃；尘土 vt. 撒；拂去灰尘 n调好的面团通过轧辊送出，压成面片，再切割成面坯，如切成直径约 5cm、厚1.2cm的圆形面坯。将这些切出来的面坯，撒上米粉或涂上油，以免粘在一起。 nthey are then stacked and packed in a suitable can. these cans are dough-tight but not gas-tight. as a result， air and carbon dioxide may and do escape so that the dough reaches and blocks the

14、 gas outlets.noutlet autlet, -lit n. 出口，排放孔 n然后把它们垒起来，装入适当的金属罐。金属罐对面团不透漏，但不是气密性的。因此空气和二氧化碳可以逸出，使面团有可能到达并堵住气体逸出口。 nfor instance， the biscuits will have so expanded as to fill the container and close the original vents for gas and the internal pressure of carbon dioxide generated by the leavening mate

15、rials will have risen to around 1 atm.n例如，罐装容器中的饼干面坯会膨胀充满整个容器，并堵住原有的泄气口。由膨松材料产生的内部二氧化碳压力将升到1atm左右。 npressure within the can will be maintained over a period of 8 weeks or so if the biscuit dough and cans are normal and the storage temperature is between 7 to 12。n只要饼干面坯和罐子正常，且贮藏温度在712之间，那么罐内的压力将维持约8周

16、以上。none of the difficulties in the manufacture of doughs using phosphate leavening agents has been the formation of visible phosphate crystals （disodium phosphate dodecahydrate）。nphosphate fsfeit磷酸盐ncrystal kristl n. 结晶，晶体；水晶；水晶饰品 adj. 水晶的；透明的，清澈的 ndodecahydrate ,dudikhaidreit十二水化物 n面团生产中使用膨松剂磷酸盐的困难

17、之一是生成肉眼看得见的磷酸盐晶体（十二水磷酸氢二钠）。 nthis crystal formation occurs at storage temperatures below 10， and is frequently most abundant at about 7。n这种晶体在贮藏温度低于10时形成，而在7左右时常常大量产生。 nthis crystallization is prevalent in the canned refrigerated doughs because of their extended storage， including normal period of t

18、ransportation and storage in the stores and homes.n罐装冷藏面团中这种结晶现象很普遍，其原因是它的贮藏期长（包括正常的运输时间和在商店及家庭中的存放时间）。 nthese visible crystals cause consumer rejection of the product because of their glass-like appearance and an uneven coloration of the baked goods which develops upon baking.nuneven ,ni:vn adj. 不均

19、匀的；不平坦的； n这些肉眼可见的晶体致使产品难以为消费者所接受，因为晶体外观象玻璃，并且焙烤时会在焙烤制品上形成不均匀的颜色。nit is found that phosphate leavened cereal doughs can be prepared. which can be kept at their normal storage temperature （i.e.， between about 7 and 12） for periods up to 12 weeks or more， and which are free from visible phosphate cryst

20、al formation.n有人发现，用磷酸盐作膨松剂制成的谷物面团可在正常的贮藏温度（即在712）下存放12周或更长的时间，并且无明显磷酸盐晶体形成。 nsuch a dough is made in the conventional manner， by mixing the ingredients such as flour， shortening， flavoring， water， the usual minor ingredients， and the chemical leavening agent， and then allowing the dough to develop，

21、 and shaping the dough as desired.n这种面团用传统方法制造，先把各种配料如面粉、起酥油、调味料、水、常用的微量配料以及化学膨松剂混合在一起，然后让面团展开，并按所要求的形状成型。nthe dough is then placed in the consumer container and sealed， then allowed to proof rapidly so that dough temperature reaches 14 to 20 as quickly as possible.nproof pru:f发面；试验；校对； n接着将面团装入小包装容

22、器并密封，让其迅速醒发，使面团的温度尽快达到1420。 nproofing involves the reaction of the chemical leaveners to provide sufficient carbon dioxide to cause the dough to expand and fill the container so as to close the gas vents.n醒发过程涉及到化学膨松剂的反应，产生足够的二氧化碳，使面团膨发充满容器，从而封住泄气口。nthe canned dough is cooled in a conditioning area，

23、 such as controlled temperature room， at a temperature above its freezing point but below 0. normally the freezing point of such doughs is about -6。n然后将罐装面团放在温控室之类的调理场所中，在高于面团冰点但低于0的温度下进行冷却。这类面团的冰点通常在-6左右。 nthe time and temperature required to condition the dough will vary dependent upon can dimensi

24、ons， net weight of the dough， formation of the dough， and refrigeration conditions used.ndimension dimenn, dai- n. 数 尺寸；容积 vt. 标出尺寸 n面团调理所要求的时间和温度随金属罐尺寸、面团净重、面团成形及所用制冷条件的不同而异。 nhowever， it is important that the temperature of the conditioning room not be below the freezing point of the dough.n但是，重要的

25、是调理室的温度不得低于面团的冰点。 nthe necessary time and temperature can be determined by withdrawing sample cans at intervals，opening them， and noting the temperature and condition of the dough.nat intervals 每隔一定的时间(或距离)；不时n面团调理所必需的时间和温度可以通过定期取样开罐、观测面团的温度和状态来确定。 nwhen microscopic crystals of disodium phosphate do

26、decahydrate are observed dispersed substantially uniformly throughout the dough， the dough is conditioned and will not exhibit visible phosphate crystals even after 12 weeks of storage.ndispersed disp:st adj. 散布的；被分散的；被驱散的 v. 分散；传播（disperse的过去分词）n当观察到有显微镜可见的十二水焦磷酸二钠微晶体明显均匀地分散在整个面团中时，那么此时面团已处于正常良好状态，

27、便不会在甚至贮存12周以后出现肉眼可见的磷酸盐晶体。 nonce the time has been obtained for a given product under given cooling conditions， the same time of treatment can be used for subsequent production.n给定产品在给定冷却条件下的调理时间一旦确定，便可将同样的时间应用于随后的生产中。 nconventional refigerated doughs can be conditioned by being held at about -7 to

28、-5 for about 48 hr.n传统冷藏面团的调理可在约-7-5下保持约48小时。 nwith a higher temperature it is recommended that the holding time be increased to 4 days.n若采用更高的温度，则建议将保持时间延长到4天。 nat temperatures of about -1 a longer holding time of about 3 days is required to obtain proper conditioning of the dough.n在-1左右的温度下，为使面团获得

29、适当的调理，要求将保持时间再延长3天左右。nafter the canned dough has been conditioned， the cans are removed from the cooling area and transferred to the usual storage area where the temperature is maintained at 4 to 10。 the cans may then be transported and the dough used in the ordinary manner.n罐装面团经调理后，可从冷却场所移到温度保持在41

30、0的普通贮藏场所，这时便可按常规方式运送罐装面团和使用面团。gas storage of fruits and vegetables ncontrolled atmosphere （ca） storage refers to the composition of the atmosphere altered from that of air in respect to the proportions of o2 and/or co2.nalter :lt vt. 改变，更改; vi. 改变；修改 n气调（ca）贮藏是指贮藏环境大气的组成在o2或co2 （或两者）的含率上是由改变空气组成而来的贮

31、藏方法。 nthe proportions are controlled； o2 usually is lower and co2 increased； nitrogen acts as an inert “filler ” ，other gases may be added in low concentrations.ninert in:t adj. 化学 惰性的；呆滞的；无效的 n. 惰性物质；无作用的成分 n各气体的含率受到控制，通常做法将o2的含率降低，将co2的含率提高，而氮气起着惰性“填充剂”的作用，还可以加入一些低浓度的其它气体。nmodified atmosphere （ma）

32、 storage is similar in principle to ca storage， except control of gas concentrations is less precise. respiratory co2 or co2 derived from dry ice accumulates and o2 decreases.nrespiratory resprtri adj. 呼吸的 n变气（ma）贮藏与气调（ca）贮藏的原理相似，只是对气体浓度的控制没那么精确而已。由呼吸作用产生的co2和来自干冰的c02累积起来，降低了o2的含量。nlipton （1975） bel

33、ieves that the modification of the o2 and/or co2 concentration in the atmosphere surrounding fresh produce is justified if the vegetable or fruit will be more valuable after ca storage than after a similar storage period in the air.n李卜顿（1975）认为：如果蔬菜或水果经ca贮藏后比在空气中贮藏相同时间后有更高的价值，那么改变新鲜农产品周围气体中o2或co2 （或

34、两者）的浓度是合理的。 nca is used most commonly to slow ripening of fruits， but appropriate mixtures of o2 and co2 also can retard the spread of certain diseases and lower the incidence of some disorders. this is usually not apparent when storage time is brief and/or when storage temperature is optimal.n reta

35、rd rit:d vt. 延迟；阻止；妨碍；使减速 vi. 减慢；受到阻滞 ndisorder dis:d n. 失调；扰乱;腐坏 nca用于水果的缓慢后熟最为普遍，但混合适当的o2和co2也能减少某些植物病害的蔓延，从而降低腐坏事故出现的机会。当贮藏时间很短或贮藏温度适宜时，通常不易见到这种不良的事故。nthe use of ca can also prevent desirable ripening， induce severe physiological disorders and cause an increases in decay when misused. each kind o

36、f vegetable and fruit has its own specific， unpredictable tolerance for atmosphere modification .ndecay dikei n. 衰退，核 衰减；腐烂，腐朽 n如果使用不当，ca也会妨碍正当的后熟，诱发严重的生理紊乱和造成腐烂率的增加。每一种蔬菜和水果都有它自己特殊的难以预测的对气体调整的承受限度。ncontrolled atmosphere storage has been commonly used to delay ripening of fruits， retard the spread o

37、f disease， lower the incidence of storage disorders and inhibit toughening and yellowing.n气调贮藏已被普遍地用于减慢水果后熟，减少病害传播，降低贮藏腐坏事故和防止变老、变韧、变黄。 nan extension of this technique is the use of packaging films to develop a microcontrolled environment in retail packages. modification of the storage environment b

38、y suitable packaging can provide storage benefits which exceed those observed with refrigeration and controlled atmosphere.npackaging films包装薄膜n这种技术的一种推广应用是零售包装中使用包装薄膜，以形成小范围的控制环境。因适当包装而改变的贮藏环境可以给贮藏带来胜过在致冷气调贮藏中能见到的好处。produce package system na package of apples can be a dynamic system in which two pr

39、ocesses， respiration and permeation， occur simultaneously. there is an uptake of o2 by the apples and evolution of co2， c2h4，h2oand other volatiles， and， at the same time，specific restricted exchange of these gases through the packaging film.nrespiration ,resprein n. 呼吸；呼吸作用 npermeation p:miein n. 渗透； 化学 渗透作用；散布性 nsimultaneously saimlteinisli adv. 同时地 nvolatile vltail n. 挥发物 n一包苹果可以是一个动态体系，在该体系中，同时进行着呼吸和渗透这两种过程；苹果吸取o2 ，放出co2 、乙烯、水份和其它挥发性物质，与此同时，这些气体透过包装薄膜进行着特别有节制的交换。 nvariables that affect respiration are： weight of apples， stage of maturity， membrane permeability， temperature