A. L. CAMIRE’s research while affiliated with University of Massachusetts Amherst and other places

ABSTRACTA quantitative HPLC method for the analysis of phytic acid in foods was developed based on the precipitation of phytic acid with ferric chloride followed by conversion to sodium phytate before injection onto a C18 reversed-phase column. Standard food grade wheat bran samples were analyzed by the method of standard addition and recovery of phytic acid ranged from 99 – 103%. 3% H2SO4 was found to be as effective as 3% TCA in the extraction of phytic acid. AAS was shown to be potentially valuable as a metal specific detector for the HPLC of phytate-metal complexes.

The effect of pH and heat treatments on the binding of iron, calcium, magnesium and zinc and the loss of phytic acid in defatted soy flour was investigated. The soy flour was found to bind more iron, calcium, and magnesium at pH 6.8 than at pH 5.0, but the reverse situation occurred with zinc. Boiling caused a significant increase in binding of zinc and magnesium at both pH values, but was pH dependent for iron and calcium. Toasting caused a significant increase in binding of zinc and calcium at both pH values and a pH variable effect on iron and magnesium. Phytic acid analysis under the same conditions suggested that the degree of binding of these minerals did not correlate with the presence of phytic acid.

Soft white and hard red wheat bran were found to contain 98.8 and 99.2% water insoluble iron, respectively. As the concentration of iron added to wheat bran was increased, less of the total added iron was bound. Ascorbic acid was found to inhibit binding of ferrous iron to wheat bran. It was found that boiling for 1 hr in a boiling water bath (BWB) had no effect on the destruction of phytic acid in wheat bran, whereas toasting for 1 hr at 178°C (350°F) and boiling for 1 hr in 1N HC1 had a significant effect.

The four major anthocyanins of cranberries were separated and purified by conventional paper chromatography. The purified individual anthocyanins were eluted from the paper by methanol-acetic acid-water (90:5:5) and concentrated on a rotary evaporator (<30°C). The individual anthocyanins were chromatographed separately and in a mixture by a reversed-phase high-pressure liquid chromate-graphic (HPLC) system. Complete separation of all four anthocyanins took less than 1 hr 40 min. A SO-ml sample of commercial Cranberry Juice Cocktail first purified by a GC-50 ion exchange column before injection into the HPLC showed the presence of two additional pigments when chromatographed.

The effect of pH and heat treatment on the binding of added food grade sources of calcium, magnesium, zinc, and iron to a standard wheat bran, cellulose, and lignin was investigated. 1% solutions of pectin and guar gum were examined for their ability to bind these metals in aqueous solution. Lignin and pectin was found to have high metal binding capacities. Metal binding to fiber was found to be pH dependent. Toasting had no effect on metal binding by cellulose, but had a significant effect on the binding of metals by lignin and wheat bran. Boiling had a significant effect on the binding of metals by cellulose, lignin, and wheat bran.