44F-1 |
The effect of storage relative humidity and popping method on the popping characteristics of commercial vendor popcorn |
T. J. LABUZA, Grade 7, Saint John the Baptist Elementary School, 845 2nd Ave. N.W., New Brighton, MN 55112 and T. P. Labuza, Dept. of Food Science & Nutrition, Univ. of Minnesota, 1354 Eckles Ave., Saint Paul, MN 55108. Previous studies have shown that the higher the moisture content of unpopped popcorn the greater the popping volume. We examined the effect of %RH of storage on popping characteristics. As a vendor, such as a movie theater, more volume means more profit. Prior work also shows improved sensory acceptance with higher moisture kernels. Unpackaged commercial vendor popcorn kernels was stored for 3 weeks at 0 to 75% RH. Popping was done in triplicate in both an oil and air popper. The time and temperature to first pop (temp by IR gun), final pop time (>5 sec between pops) and number of unpopped kernels was measured. It was shown that the highest popping volume (~3,300cc per 100g) occurred between 62% and 75% RH while popcorn started at 0% RH gave a volume of 1,250-1,450cc, less than half. The temperature of popping decreased from 205°C for 0% RH storage vs. 165°C for 75% RH, yet despite the lower temperature the volume was 2 fold higher. The air popper performed better in all cases as compared to the oil popper: more volume (~200cc), faster initial and final pop time (~20-40 seconds in each case) and less unpopped kernels. The number of unpopped kernels was 7 fold more when stored at 0 vs. 75% RH thus decreasing volumetric yield. Conclusions show that popcorn should be humidified to around 60% and 75% RH before packaging which gives about 14% moisture content (wb). The commercial vendor popcorn out of the bag (~73%ERH) yielded 3,250cc or 295cc per $.01 (FOB). As for retail non-microwave popcorn, the most expensive popcorn at 13.9% moisture gave 4,250cc per 100g at 110cc per $.01 retail cost while the least expensive which gave 3,800cc per 100g at 260cc per $.01 cost.
Session 44F, Product Development
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