摘要:

ABSTRACTBy paired comparison methods, concentrations of 0.75% and 0.86% calcium cyclamate and of 0.17% and 0.19% aspartame were equivalent in sweetness to 10% sucrose in distilled water at 3° and 22°C, respectively. Inherent bitterness of the compounds prevented precise assessment of relative sweetness for sodium saccharin in distilled water, and for the saccharin and cyclamate in flavored drinks. By application of linear regression to the paired comparison data, 0.07% aspartame was calculated as equal in sweetness to 10% sucrose in lemon, strawberry and orange drinks. Because the underlying bitterness of saccharin interfered with assessment of its sweetness, a time‐intensity technique was applied. Using a chart recorder to monitor time, time‐intensity (T‐I) measurements were made of the intensity and the duration of sweetness, bitterness, sourness and flavor in distilled water, and the same characteristics, plus flavor in three flavored drinks, and two flavored gelatins, sweetened with sucrose, cyclamate, or saccharin. T‐I curves for the sensory properties of aspartame closely resembled those for sucrose in all media. Cyclamate and saccharin imparted a marked, persistent bitterness to all carriers. In gelatin, samples containing 18% sucrose were firmer initially and took longer to manipulate to a liquid in the mouth than did gelatins containing 0.105% aspartame, 0.55% cyclamate, or 0.05%

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09732.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTTwo descriptive sensory methods, anchored (deviation from a sucrose reference) and unanchored, were used to quantify differences in aroma, flavor and aftertaste in five media – strawberry, lemon and orange drinks, and strawberry and orange gelatins – varying in type of sweetener. With both methods, samples sweetened with sodium saccharin deviated the most from the sucrose standard, those sweetened with aspartame the least, and calcium cyclamate was intermediate. In general, drinks sweetened with sucrose or with aspartame could be characterized as “sweet‐clean”, and those sweetened with cyclamate or with saccharin as “sweet‐chemical” and “bitter”. Gelatins containing synthetic sweeteners generally were more astringent, bitter and sour, with less strawberry flavor, and were significantly less hard, springy and viscous than those sweetened with sucrose. In all media, more significant differences were observed among the sweeteners with the anchored method than with the unanchored procedure. Advantages and limitations of these two quantitative descriptive proce

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09733.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTA Brabender Visco/amylo/Graph model VA‐V modified to accommodate higher torque was used to study gelatinization of wheat flour and wheat flour components in limited water concentration (solid concentration between 50.2 and 59.7%). Other solid ingredients in the mixture were sugar and molasses. Effect of ingredient variables (starch content of flour components, fraction of flour components or flour in the flour‐sugar mixture, and moisture contents of the mixture) and cooking variables (rpm of the cooker, temperature above the pasting temperature, and duration of cooking after reaching the pasting temperature) on maximum consistency and consistency of the paste at the end of cooking and moisture loss during cooking were investigated. Second order polynomial equations expressing relationships between ingredient and processing parameters are developed from the experimental results. Water content, flour content of solids, and starch content of flour all affect the consistency of the flour‐sugar‐water paste. The pasting temperature of starch or flour in sugar solution is a function of sugar concen

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09734.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTAlpha‐amylase is recognized as a major contributor to the results of viscometric tests on wheat flour. The use of a simple, rapid colorimetric α‐amylase assay to routinely predict amylograph viscosity was studied. Particle size and overall composition of malt fractions did not affect the colorimetric test; and protein content of wheat flours did not consistently affect amylograph viscosity. Equivalent levels of α‐amylase from different malts had similar effects on amylograph viscosity of a single flour; however, a single malt produced various peak viscosities in different flours. The data suggests that the viscosity may be influenced by environmental conditions which alter the starch properties and thereby effect viscosity. Consequently, the colorimetric α‐amylase assay did not reliably predict amylograph viscosity of flours from various locations and en

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09735.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTThe effects of gamma‐irradiation on chemical composition of wheat lipids and on the changes in chemical properties of lipoprotein complex, were studied. No appreciable changes in total lipids in wheat, irradiated up to 1 Mrad, were observed. However, a significant increase in free lipids with concomitant decrease in bound lipids was observed. Separation of nonpolar and polar lipids into microconstituents did not show significant variations. Purothionines, extracted from lipid fractions of wheat flour exhibited several protein bands on electrophoretic separation; most of them disappeared at high dose level (1 Mrad). This may result in the disruption of lipid‐purothionine complex. When bread dough was allowed to rest for 2 hr, aggregation of low molecular weight protein entities took place; this could strengthen the structure of lipoprotein complex during resting and bak

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09736.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTComparative sensory and objective evaluations of bread prepared from wheat flour, irradiated at different doses, have been carried out. The preference of bread decreases with higher radiation dose (1 Mrad) due to increase in off‐flavor intensity. Total carbonyl contents are increased in irradiated products. A significant inverse correlation between consumer preference and total carbonyls as well as GLC headspace vapor analysis, is established. An attempt has been made to postulate a mechanism for the excessive formation of volatiles, imparting off‐flavor in bread from irradiated wheat. It is suggested that they may arise from the volatile degradation products of amino acids and proteins or by their interaction with reducing sugars, the ultimate radiation‐induced breakdown product of s

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09737.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTResearch is described for the extraction of pectin from lime and lemon peel with nitric acid. Temperature and time were varied while extraction acidity remained constant at pH 1.6. For those extraction conditions that resulted in maximum jelly units, yield of pectin as alcohol precipitate, jelly grade and yield as 150 grade pectin were tabulated. Yields of pectin from lemon peel decreased (6.49% in July to 2.55% in November) with increasing fruit maturity. Comparative data were also obtained for pectins extracted from commercially leached peel and the corresponding rotary dried peel. Loss due to drying peel was from 7.7–10.6% in yield of 150 grade pecti

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09738.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTThe kinetics of deesterification of high‐ester citrus pectin, using acid, ammonia, or a treatment with acid followed by ammonia in isopropanol was studied with respect to the changes in methyl ester groups, molecular weight, and the formation of acid amide groups. It was found that: (1) Higher concentrations of acid or ammonia at low temperature resulted in less depolymerization for a certain decrease in ester groups; (2) The conversion of methoxyl groups to acid amide groups approached unity as temperature was lowered and ammonia concentration increased. A linear relationship between the increase in amide content and the decrease in esterification was found; (3) In treatments using hydrochloric acid followed by ammonia, a long acid treatment and a short ammonia treatment resulted in a maximum retention of apparent molecular weight. However, this treatment gave a smaller number of acid amide groups in the final product. Depending on the selection of ammonia concentration and temperature, a wide range of acid amide levels was possible. It was also possible to predict the conditions needed for deesterification to give certain apparent molecular weights and ratios of amide levels to ester level

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09739.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTThe microstructure of soybean protein aggregates was examined by the optical microscope and the scanning electron microscope. The effects of heat and coagulating agents on the microstructure of the aggregates and on the physical and textural properties of the protein curd were investigated. Isoelectric point precipitation and calcium coagulation did not change the globular structure of the native soybean protein. However, heating induced the destruction of the native protein body. Heat denaturation of the protein was necessary in forming the network structure of the aggregates. When the protein aggregates were frozen, their structure became better defined and enlarged. The three dimensional network structure of the aggregate derived from heated soybean protein showed a low sedimentation rate, high curd yield, high water‐holding capacity, low value of hardness and high springiness compared to the unheated precipitates of globular structur

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09740.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

ABSTRACTGerminated greengram, cowpea and chickpea were studied for chemical characteristics after cooking, by estimating the changes in phytins, Ca++, Mg++and pectin contents. Cooking time was drastically reduced on germination in chickpea, while an inverse effect was observed in greengram and cowpea. The phytin content decreased on germination. No appreciable change in phytin P/Total P value was seen on cooking. Ca++content was reduced on germination and cooking in the three legumes, while Mg++content was relatively unaltered. A combined interaction of these chemical parameters, expressed as “PCMP number” was found to correlate with the cooking behavior of the legumes stud

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1978.tb09741.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY