淀粉发酵法制取甘油

随首市场对甘油(丙三醇)的需求量不断增加,且皂化甘油产量又不断下降,为缓解供需矛盾,开发甘油新来源,以淀粉为原料经酶法液化、糖化后,以亚硫酸盐诱导进行甘油发酵,再经处理分离、精制,能获得较好的甘油产品。本文介绍淀粉发酵法制取甘油的工艺及化学原理。     

THE SURFACE DECONTAMINATION OF SEEDS TO PRODUCE AXENIC SEEDLINGS

A variety of sterilizing agents were tested to develop a standard procedure for surface decontaminating seeds to produce axenic seedlings. The use of calcium hypochlorite (0.5% phosphate buffer, pH 6) for 10 min followed by three sterile water rinses was among the most effective agents, and it did not injure some species as did sodium hypochlorite, formaldehyde, ethylene oxide and mercuric chloride. Some species contained internal microbes requiring severe treatments which killed or injured the seedling, while other species were “decontaminated” with a sterile water rinse. The percentage of seeds with internal microbes varied considerably among plant species, seed lot, and the length of seed storage. Thus, with seeds not easily decontaminated, screening of additional seed lots would be more profitable than testing additional decontamination agents. Release of microbes from the seed's interior is associated with germination, and microbial testing must last at least 11 days. Nutrient agar permitted growth, although the seedlings outgrew petri plates too quickly for adequate certification. These seedlings were transferred to nutrient agar in quart jars in which an internal pool of broth was periodically agitated to permit microbial sampling of the leaves while the plant grew.     

EFFECT OF LIKING, BRAND NAME AND PRICE ON PURCHASE INTENTION FOR BRANDED, OWN LABEL AND ECONOMY LINE CRISP SNACK FOODS

The effect of liking, brand and price label on purchase intention were studied on crisp snacks in branded, supermarket own label and economy form. Unlabeled assessment segregated the products into differing levels of liking which did not correspond to marketed price and brand location. Level of liking dominated purchase intention under partial label (price or brand alone) and full label (price with brand) conditions. Relative and derived purchase intention measures gave clearer label effects with significance for brand and price. Consumers who professed higher price awareness were more influenced by price, but those professing brand as a main purchase intention reason gave more weight to liking. Results from analysis of purchase intention and degree of liking measures according to private body conscious level were inconclusive.     

综合利用薯芋淀粉生产肌苷的研究

本文报道综合利用野生薯芋属植物盾叶薯芋(Dioscorea zingibensisC.H.wright)和穿龙薯芋(Dioscorea nipponica Makino)中的淀粉生产肌苷(Inosine)的方法。将薯芋原料带水磨碎,在水中筛分得到皂甙淀粉浆,用稀酸水解该物质使淀粉糖化,分离后得到糖液和糖渣。糖液加氮源和无机盐,发酵生产肌苷。糖渣再水解提取薯芋皂甙元。     

多菌种混合发酵无醇饮料的研究

以大麦芽、大麦和大米为主料,优质红茶为辅料,依据微生物生理代谢与生态的基本原理,选择了三个菌种混合发酵,开发了一种新型发酵无醇饮料。采用的三个菌种是：酵母菌（Ｓａｃｃｈａｒｏｍｙｃｅｓｃｅｒｉｖｉｓｉａｅ）,嗜酸乳酸菌（Ｌａｃｔｏｂａｃｉｌｌｕｓａｃｉｄｏｐｈｉｌｕｓ）,弱氧化醋酸单胞菌（Ａｃｅｔｏｍｏｎａｓｓｕｂｏｘｙｄａｎｓ）。将上述菌种按一定比例（１：１：２）接种,接种总量为发酵基质的１０％,控制发酵温度２０－２５℃,发酵时间５天,即可制成风格独特、口味纯正的新型发酵无醇饮料（含醇量＜１％）。     

USING ANDERSON'S STATISTIC TO COMPARE DISTRIBUTIONS OF CONSUMER PREFERENCE RANKINGS

Anderson's statistic, which compares distributions of ranks, is generalized to cope with tied rankings. A simple example is given to illustrate the calculations involved. In market research work it is often important to compare distributions as well as mean values. Comparison of distributions can indicate either market segmentation or product variability.     

发酵白酒糟生产饲料蛋白的优良菌种的筛选

采用常规方法从1000多株菌(包括丝状真菌、酵母菌、链霉菌、细菌)中筛选到一批优良菌种,并进行了单菌发酵、多菌株组合发酵,不同原料配方发酵试验。在实验室条件下,发酵产物的粗蛋白含量高达35.9％,比原料本身的粗蛋白含量高50％以上,比所用培养基的粗蛋白含量高30％,发酵产物的粗纤维含量降低率为15％;粗脂肪含量为5.5％左右;产率达80％以上。结果证明,筛选到的菌株确是发酵白酒糟生产饲料蛋白的优良菌种。     

THE DOLLAR VALUE OF PRODUCT QUALITY: THE EFFECT OF PRICING VERSUS OVERALL LIKING ON CONSUMER STATED PURCHASE INTENT FOR PIZZA

This paper investigates the combined effects of price and product quality (overall liking) on the acceptance of restaurant pizza pies. The results reveal that when a panelist evaluates both liking and purchase intent (with price attached to the purchase intent question), product quality is a significantly stronger determinant of purchase intent than is the stated item price. For instance, a 10% increase in product quality (viz., liking) has the same effect on purchase intent as a 20% reduction in item price. The results are surprising, because for other categories investigated by the same method price is a significantly greater determinant of purchase intent. In terms of predictability, 57% of the variation in purchase intent ratings is accounted for by liking, 24% of the variation is accounted for by price, and the remaining 19% is due to error.     

栀子组织和细胞培养生产天然食用色素的研究——Ⅰ.愈伤组织培养的研究

在诱导出愈伤组织的基础上,对各种不同的培养条件进行分析研究,考察它们对愈伤组织生长和栀子黄色素产生的影响,筛选出适宜的生长培养基:B_5+IBA 1mg/l+KT0.23mg/l、MG-5+IBA 1mg/l+KT 0.23mg/l、B_6+IAA 1.5mg/l和生产培养基:M-9+IAA 1mg/l、M-9+IAA 1.5mg/l.并且,获得了几个色素含量较高的愈伤组织系。另外,还研究了含色素和不含色素的愈伤组织在培养过程中的过氧化物同工酶的差异。     

USE OF PURCHASE PREFERENCE OPTIONS TO INCREASE NO PREFERENCE FREQUENCIES IN PLACEBO PREFERENCE TESTS

Besides responses to the different stimuli being tested in a paired preference test, responses to identical placebo stimuli can be used as a screening tool to identify biased consumers. Those consumers who give preference responses to identical stimuli can be assumed to be biased. Accordingly, only the data from unbiased consumers need to be considered for the different stimuli. The problem with this procedure is that the sample size is reduced. The goal of the present research was to see whether using options associated with purchase intent, elicited a greater number of No Preference responses to identical placebo stimuli. It was found that they did. The increase was large when the preference options implied exclusivity. In conditions where the preference strength options were not so strong, the frequency of No Preference responses dropped accordingly.

PRACTICAL APPLICATIONS

A problem with paired preference testing is the tendency of consumers to give false preferences, which produces the seriously misleading overestimation of the proportion of consumers who have preferences for one or other of the products being assessed. The placebo condition is an important control for alleviating this problem. The statistical analysis can be improved by finding a protocol that maximizes the proportion of No Preference responses in the placebo condition. The key finding here is that using purchase intent questions rather than preference questions may possibly provide a way of achieving this aim.     

固定化共生发酵无醇饮料的研究

以大麦和大米为主料,优质红茶为辅料,采用海藻酸钠包埋法固定酵母菌、嗜酸乳杆菌、弱氧化醋酸菌,混合装填固定化细胞反应柱,连续发酵生产无醇饮料。试验表明：麦茶汁１２°Ｂｘ,ｐＨ６５,２５℃,反应柱内固定化各菌种凝胶比例为酵母菌：嗜酸乳杆菌：弱氧化醋酸菌＝０．７：１：２,停留时间９～１３ｈ,相当于游离细胞发酵１０ｄ的效果。流出液含Ｌ－乳酸１．６５～１．９８ｇ／Ｌ,总酸２．６２４～３．０３２ｇ／Ｌ,酒精０７％～１．３２％。制成的新型发酵无醇饮料呈淡黄色,泡沫洁白细腻,含有多种人体必需氨基酸和维生素,以及具有保健作     

THE USE OF TISSUE CULTURES TO PRODUCE VIRUS-FREE CLONES FROM INFECTED POTATO VARIETIES

By growing the excised apical meristems of sprouts from the potato varieties King Edward and Arran Victory, infected respectively with potato paracrinkle virus and potato virus S , virus-free plants were obtained. Although the method failed to produce virus-free plants from varieties infected with potato virus X , this virus also seems not to be present in apical meristems, for no virus could be demonstrated in callus tissue that developed from excised meristems less than 200 μ across. The concentration of tobacco mosaic virus in tomato roots and tobacco stems is also much less near the growing point than in older cells, but there is no evidence that the meristematic region is virus-free.     

THE ECO‐EVOLUTIONARY RESPONSES OF A GENERALIST CONSUMER TO RESOURCE COMPETITION

This article explores the combined evolutionary and ecological responses of resource uptake abilities in a generalist consumer to exploitative competition for one resource using a simple 2‐resource model. It compares the sizes of ecologically and evolutionarily caused changes in population densities in cases where the original consumer has a strong or a weak trade‐off in its abilities to consume the two resources. The analysis also compares the responses of the original species to competition when the competitor's population size is or is not limited by the shared resource. Although divergence in resource use traits in the resident generalist consumer is expected under all scenarios when resources are substitutable, the changes in population densities of the resources and resident consumer frequently differ between scenarios. The population of the original consumer often decreases as a result of its own adaptive divergence, and this decrease is often much greater than the initial ecological decrease. If the evolving consumer has a strong trade‐off, the overlapped resource increases in equilibrium population density in response to being consumed by a generalist competitor. Some of these predictions differ qualitatively in alternative scenarios involving sustained variation in population densities or nutritionally essential resources.