摘要:

AbstractEuropean maize wet‐milling industries process 3.2 million t of maize per year. For this supply the world market share decreases progressively to the E. C. market's advantage. Manufacturers have not always a long experience of such maize, the quality of which is variable.The increasing number of cultivated varieties, the changes of maturity conditions according to years, and the evolution of the harvesting‐drying‐preserving sequence towards an industrialisation, emphasize the variations of E. C. maize wet‐milling quality.The immediate care of manufacturers is therefore to have available simple and rapid methods for the appreciation of this quality. Then, these methods will have to be applied to the determination of good conditions of maize production for this industry.Ensuing french studies, a concerted research program has been developed since the beginning of 1973 on the basis of the previous remarks. The coordination of these studies is undertaken by a Technical Committee of E. C. Maize Starch Industry grouping research institutes, i. e. I. T. C. F. (Technical Institute for Cereals and Forages, France), I.N.R.A. (National Institute of Agronomic Research, France), F.R.I.C.I. (Federal Research Institute of Cereal Industry, Germany), professional associations, i.e. A.G.P.M. (General Maize Growers Association, France), A.A.M. (Association of the Maize Starch Industries of the E.C., Belgium), and a representative of manufacturers for each member country.The work done in 1973 represents the preliminary phase of these studies, and was carried out on samples from 1972 harvest, crop year abnormaly unfavourable for maize growing. The results obtained are therefore mostly on a methodology level, and the main purpose of the 1974 research program is to confirm and complete these infor

ISSN:0038-9056    

DOI:10.1002/star.19740261102

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

Abstract5‐Hydroxymethylfurfural as a Chemical and Technological Indicator Substance in Acid Starch Hydrolysis.From the point of view of yield the formation of 5‐hydroxymethylfurfural (HMF) is of no great importance in acid starch hydrolysis. As the percentual decomposition of glucose compared to HMF remains almost constant within the range of technological conditions, whereas with different reaction conditions highly varying amounts of coloring matter and HMF will occur, HMF has to continue reacting differentially.Following a characterization of the chemical individual HMF, its formation and decomposition at various pH‐values, it is shown that in the technological process the HMF‐amount of starch hydrolysates is strongly dependant on production conditions. Especially compensation of high temperatures by means of increased acid concentrations as well as improving turbulence in the pasting phase will lead to a substantial decrease in the formation of HMF. Contents of coloring matter and protein are much less influenced, which makes HMF‐content a true chemical‐technological indicator.Participation of HMF in the formation of coloring matter in starch hydrolyzates obviously is only important in the high‐acid range. Discolorations of hydrolyzates in the pH‐range around 5 do not coincide with changes in the HMF‐content as is the case in the acid range of

ISSN:0038-9056    

DOI:10.1002/star.19740261103

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractThe glucoamylase system of black koji mold was fractionated into four kinds of glucoamylase by using the corn starch adsorption technique supplement by DEAE‐cellulose column chromatography. One of these fractions, referred to as glucoamylase I, had a strong debranching activity and is highly active in raw starch digestion.The raw waxy corn starch digestion by glucoamylase I was accelerated by adding α‐amylase or isoamylase. The raw non‐waxy corn starch digestion by glucoamylase I was accelerated by α‐amylase but not so much by isoamylase as by α‐amylase.On the other hand, another fraction, referred to as glucoamylase II, had very weak debranching activity and was most feeble in the digestion of raw starch. The raw waxy corn starch digestion by glucoamylase II was very weak, but was accelerated extremely by adding isoamylase, but not

ISSN:0038-9056    

DOI:10.1002/star.19740261104

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractMean values of damaged starch of 49 samples of wheat whole meals determined by the A.A.C.C., Stewart and the colorimetric method of Williams and Fegol were: 11.4%, 9.96% and 1.44 (O.D.), respectively. Statistically high significant positive correlations between the values of different methods (+ 0.80 to + 0.91), maltose values v. damaged starch (+ 0.89 to + 0.94) and between damaged starch and absorption (+ 0.58 to + 0.74) were obtained. Regression analysis of maltose on damaged starch and of absorption on damaged starch and protein contents of whole meals were statistically highly significant.

ISSN:0038-9056    

DOI:10.1002/star.19740261105

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractThe rate of hygrogenation was highly increased by carrying out the reaction at pH 8. Addition of some metals and metal salts, especially calcium sulphate, highly increased the rate of hydrogenation at pH 6.8.

ISSN:0038-9056    

DOI:10.1002/star.19740261106

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractThe reaction between starch xanthate and alkyl diepoxide formed gels in concentrated solution (6–8%) or turbid suspensions in dilute solution (0.1–1,0%); the gelling varied with the nature of the epoxide. The gel or suspension was dispersed and added to wood pulp suspension and therefrom paper products of improved strength characteristics were formed. Also the reaction was conducted in the presence of paper furnish. Handsheets made from furnish containing a 2.5% additive level based on fiber content had burst, folding endurance, and wet and dry breaking length values 1.6, 4.6, 4.2 and 1.4 times, respectively, those of control papers. Improvement in properties was somewhat independent of the xanthate's degree of substitution but dependent on the reaction time (either separate from or in presence of fiber) and the order of addition of epoxide and xanth

ISSN:0038-9056    

DOI:10.1002/star.19740261107

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractStorage of potatoes in controlled atmosphere.The interim results obtained from trials with CA‐storage are reported. Storage atmospheres with low O2and increased CO2contents largely inhibit the sprout growth of potatoes kept at a temperature of 9 °C so that chemical sprout suppressants may possibly be dispensable.Storage atmospheres with too high a CO2content cause an intense rise of the saccharose content and lead to increased decay. With tolerable storage atmospheres these disadvantages can be avoided.The remaining questions shall be answered in further trials which shall also help to bring CA‐storage to perfection for its application in prac

ISSN:0038-9056    

DOI:10.1002/star.19740261108

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

摘要:

AbstractCriterions to evaluate the quality of dried potato products for human consumption.The swelling properties of dried potatoes were tested. In the first part of this work the importance of starch and dry matter for the swelling behavior of dried potatoes is reported. To evaluate these experiments the correlation coefficient is used. 140 samples of dried potatoes were tested. Continuing the test series dried potatoes manufactured from one potato variety, what is devided into different classes of specific gravity were examined. The used physical conditions for estimating the swelling behaviour are the “swelling number” and the “rehydration value”.The central point of the second part is a theory to explain the phenomena of swelling for itself. This theory tries to answer the basic question how to influence the swelling behaviour of dried potatoes. The results of these experiments are interpertated by the postulation that two reaction typs estimate the swelling of dried potatoes:1The first reaction depends on the surface and is exothermic.2The second reaction does not depend on the surface and is endo

ISSN:0038-9056    

DOI:10.1002/star.19740261109

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19740261110

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19740261111

出版商:WILEY‐VCH Verlag GmbH    

年代:1974

数据来源: WILEY