Field Pea Starch Research Articles

Chemical and Enzymatic Modifications of the Pasting Properties of Legume Starches

AbstractRefined legume starches were evaluated for their Brabender Visco/Amylograph properties in their native form and after chemical and enzymatic pretreatment during incubation for 20 h at room temperature. Although exhibiting the characteristic restricted paste viscosities of legume starches, native lentil starch showed much higher viscosity parameters than navy bean starch while field pea starch had very low, stable viscosities. Pretreatments with mineral acids, alkali or enzymes failed to significantly alter the amylographs of the 8% slurries (w/v). Removal of surface lipids on the refined starch granules with propanol/water (3:1 v/v) or chloroform/methanol (2:1 v/v) increased paste viscosities substantially, as did the complexation of the starches with palmitic acid or glyceryl monopalmitate. None of the treatments resulted in complete dissolution of the starch granules and the modified starches showed no improvement in gel syneresis during storage.

Efficiencies of Solvent Systems for Extraction of Legume Lipids

AbstractTen solvent systems representing a wide range in polarity were highly variable in their abilities to extract the total lipids from field pea and lentil flours and starches. Propanol/water (3 : 1v/v) extracted the most lipid from lentil flour and both legume starches. Chloroform/methanol (2:1 v/v) and benzene/ethanol (4:1 v/v) gave consistently high recoveries of total lipids from both flours but appeared to be less effective with starches. Fractionation of the purified flour lipids demonstrated that propanol/water extracted phospholipids and glycolipids quite efficiently but chloroform/methanol and benzene/ethanol gave high recoveries of both nonpolar and polar lipids. These neutral, phospho‐ and glycolipids from the two legume flurs were highly polyunsaturated, containing 35–50% linoleic and 5–21% linolenic acid, and would be susceptible to oxidative rancidity. Purified lipids from legume starches were recovered as neutral lipids primarily and yields were very low.

Lipid Composition of Field Pea (Pisum sativum cv Trapper) Seed and Starch

AbstractThe total lipids in field pea seeds and refined starch were extracted by five aqueous/organic solvent systems and the greatest yield of total. neutral and polar lipids was obtained with hot n‐propanol‐water (3:1 v/v). Lipids extracted from field pea seeds represented 2.9% of the seed weight and consisted of 43.2% neutral lipids, 3.2% glycolipids and 53.6% phospholipids. The major components of the three fractions were 70% triacylglycerol in neutral lipid, 28% esterified sterol glycoside in glycolipid and 55% phosphatidylcholine in phospholipid. The purified starch fraction contained 0.22% surface lipids and 0.09% internal lipids. The surface lipids were primarily sterol esters and free fatty acids while only free fatty acids were found in the internal lipids. The ability of lysophospholipids and fatty acids to complex with field pea starch was demonstrated by differential scanning calorimetry and X‐ray diffraction, respectively.

Effects of Hydroxypropylation on Themal Properties, Starch Digestibility and Freeze‐Thaw Stability of Field Pea (Pisum sativum cv Trapper) Starch

AbstractField pea starch with an amylose content of 34.2% was hydroxypropylated with propylene oxide and sodium hydroxide to give products with molar substitutions (MS) ranging from 0.04 to 0.12. Increasing the degree of MS resulted in progressive decreases in enthalpy of gelatinization. gelatinization temperatures, pasting temperatures and syneresis. and increases in paste viscosities at 95 and 50°C. The digestibility with a‐amylase decreased with increases in MS only up to the level of 0.08 and further increases in MS caused an increase in digestibility which was higher than that observed for native starch. These results were confirmed by scanning electron microscopy on hydrolyzed starch.

Effect of Cross‐Linking on Functional Properties of Legume Starches

AbstractRefined starches from lentil, fababean and field pea contained 38.5, 32.0 and 34.2% amylose, respectively, where the water binding capacities, swelling powers, susceptibilities to amylase digestibility and amylograph viscosities were in the order: lentil > fababean > field pea. This evidence and the X‐ray diffraction data suggested that the degrees of molecular association between starch chains, especially amylopectin, followed the order: field pea > fababean > lentil. Cross linking with phosphorus oxychloride decreased water binding capacity, swelling power, α‐amylase digestibility and 95°C viscosity in the amylograph but increased the degree of set‐back. X‐ray diffraction patterns indicated that cross linking occurred mainly in the amorphous regions of the starch granule. Scanning electron microscopy showed that cross linking hindered amylose exudation. The stable hot paste viscosities of cross‐linked starches would be of value where low pH and high temperature are employed during pressure cooking or sterilization while the low degree of set‐back of field pea starch should improve the freeze‐thaw stability and textural quality of frozen foods.

Digestibility of Raw and Cooked Starches from Legume Seeds Using the Laboratory Rat

The in vivo digestibility and growth responses to diets containing raw and cooked legume starches were determined using male Wistar rats. These starches were obtained from seven legumes including smooth- and wrinkled-seeded field peas, navy beans, kidney beans, garbanzo beans, mung beans and lentils. Wheat and potato starch diets were fed for comparative purposes. With the exception of potato and the field pea starches, rats fed uncooked starch diets had higher weight gains than those fed cooked starch diets. The starches from wheat and all legumes, excluding the high-amylose wrinkled pea, were nearly 100% digestible but the legume starches reduced the digestibility of casein protein by 3 to 4%. Raw potato starch was shown to be only 57% digestible. The starches from potato and wrinkled pea reduced the digestibility of casein protein to 87% and gave high cecum weights. These characteristics were not altered by cooking the starch of wrinkled pea. The starches of smooth-seeded peas, lentils and all beans were highly digestible, showed no adverse effects on growth and were comparable to wheat starch in this evaluation.