A high performance liquid chromatographic method has been developed to quantify the major organic acids in potatoes oxalic, citric, malic, fumaric and ascorbic acids. Tubers were extracted with 95% ethanol:tiater:concentrated sulfuric acid 60:40:0.2 followed by injection on an Aminex HPX-87 column with a mobile phase of 0.018N sulfuric acid. Ascorbic acid was detected at 260 nm while the other four acids were quantified at 210 nm unless fructose was present at a concentration of 6 mg/g or higher, in which case 220 or 230 nm was used. Greater than 90% recovery was observed for all acids with most recoveries near 100%. The method has been shown to be very reproducible with the CV% ranging from 1.3-12.3 while the majority were below 4%. Analyses of several potato varieties have shown a wide variation in acid content among varieties.

Twelve samples of raw and cooked potato peels from commercial potato varieties were analyzed for their ol-chaconine and ol-solanine content by high-performance liquid chromatography (HPLC). Raw peels contained 1.30-56.67 mg/lOOg peel (wet weight) cu-chaconme and 0.5-50.16 mg/lOOg peel (wet weight) or-solanine. Raw flesh from the same potatoes contained 0.02-2.32 mg/lOOg flesh (wet weight) ol-chaconine and 0.01-2.18 mg/lOOg flesh (wet weight) of ol-solanine. Peels were cooked by baking, frying and bakingfrying. The two types of fried peels contained more cY-chaconine (2.18-92.82 mg/lOOg cooked peel) and cY-solanine (1.09-72.09 mg/lOOg cooked peel). Four commercial potato peel productswedges, slices, fried peels and baked-fried peels -contained 3.60-13.71 mg a-chaconine/lOOg cooked product and 1.60-10.48 mg or-solanine/lOOg cooked product.

The effect of processing method (freezing vs canning) and storage time (day 1 or 10 months) on the proximate composition and the vitamin and mineral content of fiddlehead greens was examined. Comparisons were made between the nutrient composition of raw and processed fiddlehead greens. The protein, ash and water soluble vitamin (niacin, thiamin, riboflavin, vitamin C) content of the fiddleheads decreased with processing. These losses were most likely the result of leaching and heat processing. Losses of water soluble vitamins, particularly niacin, was the greatest in canned fiddlehead greens. The mineral content (K, Mg, P) was substantially reduced by processing. Storage for up to 10 months resulted in a significant decrease in the moisture, crude fiber, and a-carotene content of frozen and canned fiddlehead greens.

Fiddlehead greens of the ostrich fern, Matteuccia struthiopteris, var. Penn., from two separate locations were analyzed for their nutrlent composition. Greens contained (in %) 87 water, 1.12 fiber, 4.23 crude protein, 4.02 ash, 3.06 carbohydrate and 0.5 fat. The fatty acid composition consisted mostly of palmitate, linoleate and llnolenate. Unsaturated fatty acids account for approximately 65% of the fatty acids associated with fiddlehead lipids. Niacin, riboflavin, thiamin, vitamin C, and vitamin A were present at concentration ranges (based on wet weight) of 4.07-5.57, 0.15-0.24, 0.018-0.024, 19.00-32.69 mg/lOOg greens and 2175-2709 I.U./lOOg, respectively. Spectrochemical analysis identified 17 minerals with potassium, phosphorus, magnesium and calcium being the most prominent. The low sodium content (0.5 mg/lOOg greens) should be noted. The high potassium to sodium ratio could make fiddlehead greens an integral part of the diet of persons requiring low intakes of sodium.

Potato starch and flour were examined as possible constituents in frankfurter formulations. Frankfurters manufactured with 3% potato starch or 1.5% potato starch plus 1.5% potato flour in place of 3% wheat flour normally used as a binder, and stored at 4-5°C for 28 days did not differ significantly in percent shrink, water, protein, fat, ash or salt. Residual nitrite levels decreased during the storage period. Total plate counts reflect residual nitrite levels since the frankfurters (3% starch) with the lowest nitrite concentration also had the greatest number of bacteria (6.4 x 106/g) on day 28. Frankfurters formulated with 1.5% potato starch plus 1.5% potato flour were rated more tender and more juicy than those made with 3% potato starch (P90.05 and PGO.01) and 3% wheat flour (P< 0.01 and P