Cold Paste Viscosity (cold + paste_viscosity)

Distribution by Scientific Domains


Selected Abstracts


COOKING BEHAVIOR OF RICE AND BLACK GRAM IN THE PREPARATION OF IDLI, A TRADITIONAL FERMENTED PRODUCT OF INDIAN ORIGIN, BY VISCOGRAPHY

JOURNAL OF TEXTURE STUDIES, Issue 1 2009
BONG KYUNG KOH
ABSTRACT Pasting profile of coarse rice, fine rice as well as black gram was carried out individually, in combination, in flour as well as in batter form, before and after fermentation by Brabender Viscoamylograph. Lowest gelatinization temperature was seen in black gram among the three commodities studied. Coarse rice registered a peak viscosity (PV) of 1,300 BU, fine rice 1,030 BU and black gram 1,080 BU. Cold paste viscosity (CPV) was highest in fine rice, lowest in black gram and intermediate in coarse rice. Breakdown (BD) was least in fine rice, highest in coarse rice and black gram lay in between. Values of total setback indicated the strong reason for use of coarse rice in parboiling as well as in idli and dosa preparations. Physical combination of black gram, with fine as well as coarse rice, reduced PV on an average to an extent of 26,30%. CPV was highest in fine rice and black gram combination compared with that of coarse rice and black gram. BD was high in the physical mix of coarse rice and black gram. In comparison with physical mix of fine rice and black gram, in the batter form before fermentation, the PV and CPV reduced by 23 and 34%, respectively, but there was no BD in this mix, indicating restricted swelling behavior in the batter before fermentation. Almost all viscographic parameters reduced before fermentation in coarse rice and black gram compared with their physical combination. Highest relative BD (BDr) was noticed in the pasting profile of black gram alone, probably because of the presence of mucilaginous principle. BDr values increased in batter form to various extents, before and after fermentation, compared with physical combination of rice and black gram. After fermentation, in coarse rice and black gram, the BDr value was low compared with that in fine rice and black gram. PRACTICAL APPLICATIONS Fermented products are commonly ingested in India, especially in the southern states. Nowadays, batter is sold in public for the sake of convenience, as it is a common breakfast preparation. The practice is to use coarse rice for the preparation of idli, a steamed fermented product. It is generally not known how the rice behaves before and after fermentation while cooking. Hence, this work was planned, and results indicated the scientific basis for the usage of coarse rice in the preparation of rice products. The behavior of batter prepared from fine rice has also been described, although it is not an economically viable option. [source]


Influence of amylases on the rheological and molecular properties of partially damaged wheat starch

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2006
Pedro Leman
Abstract The effects of Bacillus subtilis, porcine pancreatic and Aspergillus oryzae ,-amylases, sweet potato ,-amylase and Bacillus stearothermophilus maltogenic amylase (BStA) on the rheological properties (measured with a Rapid Visco Analyser) of partially damaged wheat starch were studied and the accompanying changes in starch molecular properties were analysed by high-performance size exclusion chromatography. Pasting and gelation of starch slurries (with an increased level of damaged starch) were significantly affected by the supplemented amylases and greatly depended on the mode of action and properties of the enzymes added. In general, at low endo-amylase concentrations, peak, hot paste and cold paste viscosities were more reduced for enzyme-supplemented partially damaged starch than for enzyme-supplemented native wheat starch, demonstrating the significance of damaged starch levels in determining amylase functionality. Higher dosages of thermostable amylases ruled out most of the differences between amylase-supplemented native starch and partially damaged starches, except for BStA. Furthermore, the (limited) endo-action of BStA determines to a great extent the rheological properties of the starch paste. These results contribute to a better understanding of (maltogenic) amylase functionality in processing (damaged) starch-containing foods. Copyright © 2006 Society of Chemical Industry [source]


Effect of Heat-Moisture Treatment and Acid Modification on Rheological, Textural, and Differential Scanning Calorimetry Characteristics of Sweetpotato Starch

JOURNAL OF FOOD SCIENCE, Issue 6 2005
Sukhcharn Singh
ABSTRACT Sweetpotato starches were characterized to understand the changes upon modification by acid and heat-moisture treatment (HMT) in the rheological, differential scanning calorimetry (DSC), and textural characteristics of starch isolated from the sweetpotato variety PSP-21 and to compare these findings with those of commercially available arrowroot starch. The native sweetpotato starch had a Type A pasting profile characterized by a high peak viscosity (PV) (741.5 rapid viscoanalyzer unit [rvu]), with a high breakdown (378.8 rvu) and low cold paste viscosity (CPV) (417.6 rvu). After HMT, there was a marked decrease in the PV (639.1), a very slight breakdown (113.5 rvu) and an increase in CPV (759.5 rvu), more like a Type C pasting profile. However, acid modification did not notably change the pasting profile of native sweetpotato starch. The DSC characteristics were also affected significantly after modifications. The gelatinization temperature parameter to onset (To) decreased significantly after HMT and acid modification. The gelatinization enthalpy decreased during HMT from 15.98 to 14.42 J/g. The gel strength of acid-modified starch was the highest compared with that of HMT and native sweetpotato and arrowroot starches. [source]


INFLUENCE OF HYDROXYPROPYL METHYLCELLULOSE ON THE RHEOLOGICAL AND MICROSTRUCTURAL CHARACTERISTICS OF WHOLE WHEAT FLOUR DOUGH AND QUALITY OF PURI

JOURNAL OF TEXTURE STUDIES, Issue 2 2009
M. L. SUDHA
ABSTRACT Puri is a traditional unleavened fried product prepared from whole wheat flour. Hydroxypropyl methylcellulose (HPMC) was used to study its effect on rheological characteristics of whole wheat flour dough and puri making quality. Addition of HPMC at 0.5 and 1.0% w/w increased the water absorption and dough stability whereas the resistance to extension and extensibility decreased. Pasting temperature, peak viscosity and cold paste viscosity gradually decreased. The moisture and fat contents of puri increased marginally. Quality parameters and sensory acceptability were monitored after 0 and 8 h of storage. Addition of 0.5% HPMC gave higher sensory scores. Microscopic observations during puri processing showed that the starch granules in the control dough were clearly visible in the protein matrix, which reduced on frying due to partial gelatinization. Microstructure of puri with HPMC showed higher gelatinization of starch. It also helped in moisture retention and hence, resulted in highly pliable and soft-textured puri. PRACTICAL APPLICATIONS Puri is a traditional unleavened fried product that is prepared by mixing whole wheat flour and water, sheeted to a desirable thickness and fried. Use of hydroxypropyl methylcellulose (HPMC) affected the whole wheat flour dough and puri making quality. It helped in moisture retention and hence, resulted in highly pliable and soft-textured puri. Microstructure of puri with HPMC showed higher gelatinization of starch. [source]


Functional properties and retrogradation behaviour of native and chemically modified starch of mucuna bean (Mucuna pruriens)

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2003
Kayode O Adebowale
Abstract Mucuna bean (Mucuna pruriens) starch was isolated and subjected to chemical modification by oxidation and acetylation. The proximate analysis of the non-starch components of the native starch on a dry weight basis was 92 g kg,1 moisture, 5 g kg,1 ash, 2 g kg,1 fat, 7 g kg,1 crude fibre and 19 g kg,1 protein. Chemical modification reduced the values for all the non-starch components except the moisture level. For all the samples, swelling power and solubility increased as the temperature increased in the range 50,90 °C. The swelling power of mucuna native starch (MNS) and mucuna acetylated starch (MAS) increased with increasing acidity and alkalinity, while that of mucuna oxidised starch (MOS) only increased with increasing pH in the acidic range. The maximal solubility of all the starches was observed at pH 12. All the starch samples absorbed more oil than water. The lowest gelation concentration followed the trend MAS < MNS < MOS. Chemical modification reduced the gelatinisation temperature (Tp), while peak viscosity (Pv), hot paste viscosity (Hv) and cold paste viscosity (Cv) decreased after oxidation but increased following acetylation. The setback tendency of the native starch was reduced significantly after chemical modification. However, the breakdown value of MNS, 65 BU (Brabender units), was lower than that of MOS (78 BU) but higher than that of MAS (40 BU). Differential scanning calorimetry studies of gelatinisation and retrogradation revealed that chemical modification reduced the onset temperature (To), peak temperature (Tp) and conclusion temperature (Tc). Oxidation and acetylation reduced the gelatinisation and retrogradation enthalpies of the native starch. The enthalpy of retrogradation of the starches increased as the length of storage increased. Copyright © 2003 Society of Chemical Industry [source]