Characterization of Pea Starches in the Presence of Alkali and Borax
| Main Authors: | , |
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| Format: | Article |
| Language: | English Slovak |
| Online Access: | http://www.viks.sk/chk/star_10_03_457_463.doc |
| Abstract: | Summaries. Refined field pea (Pisum sativum L.) starches were prepared from air-classified pea starch by washing or from whole pea by wet milling, and analyzed for their physico-chemical and pasting characteristics in the presence of alkali and borax. Commercial corn and high amylose corn starches were included in the study for comparative purposes. The two pea starches exhibited similar physicochemical characteristics. Amy-lose content markedly influenced pasting and other characteristics of the corn starches. Pea starch and high amylose corn starch exhibited little viscosity development during pasting in deionized water. The presence of alkali or borax significantly altered the peak viscosities and cold paste stabilities of all four starches in a concentration dependent manner. Alkali and borax increased peak and cold paste viscosity and reduced syneresis in all cases. Conclusions. The results indicated that, in general, the isolation process employed, i.e. air classification/washing or wet milling, did not impact significantly the physicochemical characteristics (solubility, swelling power, amyiose leaching) of pea starches. Amyiose content was a significant determinant of the physicochemical characteristics of corn starch due to the highly restricted swelling properties of high amyiose starch. Pea and corn starches reacted in a concentration dependent manner to the presence of alkali or borax during pasting. In most cases, a higher alkali concentration increased peak viscosity, reduced the temperature at peak viscosity, and reduced the cold paste viscosity of higher amyiose starches due to the loss of their restricted swelling properties. Development of high cold paste viscosity was observed in most borax-treated starch gels. The presence of borax also increased the tackiness, cohesiveness and clarity of starch gels. Alkali and borax improved significantly the refrigerate-warm/freeze-thaw stabilities of all samples treated. The WAC-Pea and WM-Pea starch gels exhibited similar syneresis characteristics under all conditions. The N-Corn starch gels exhibited superior freeze-thaw stability compared to HA-Corn starch gels, and similar refrigerate-warm stability in the presence of alkali or borax. |
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| ISSN: | ISSN 0038-9056 |
