• Korean Journal of Human Ecology
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• v.1 no.2
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• pp.89-99
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• 1998

This study was carried out to investigate some antioxidative effects of stewed pumpkin juice (SPJ) and the SPJs added with ginger (SPJ-G), onion (SPJ-O), jujube (SPJ-J) or boxthorn (SPJ-B), respectively, on the lipid oxidation of soybean oil (S) and mackerel pike boiled ground (MPBG). Antioxidative substances of SPJ were extracted by using the two solvent layers of n-hexane:acetone (1:1)(H) and methanol:water (7:3)M. The antioxidative effects of the extracts were observed by the peroxide value (P.O.V.) and thiobabituric acid (T.B.A.) value. The P.O.V. and T.B.A. value of two solvent extracts of S and MPBG showed significantly lower than those of S and MPBG. The SPJ showed very distingnished antioxidative effects. It was considered that melanoidine extracted by using methanol:water (7:3) solvent as well as carotenoid extracted by using n-hexane:acetone (1:1) solvent had an antioxidative effect. During storage, T.B.A. value of MPBG significantly increased, while that of MPBG-SPJ significantly decreased more than that of MPBG. T.B.A. value of MPBG-SPJs decreased much than that of MPBG-SPJ, SPJ-O, SPJ-G, SPJ-J and SPJ-B, in order of abundance, showed higher level of antioxidative effects than SPJ. (Korean J Human Ecology 1(2):89∼99, 1998)

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.1-9
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• 1998

This study was designed to determine the most suitable manufacturing conditions of stewed pumpkin juice(SPJ) in terms of nutrition and taste. Well ripened pumpkin was heated for 3, 4, 5, 6 and 7 hours in a pressure cooker and then extracted and packed in retort pouches. These were kept at 4$^{\circ}C$ and 28$^{\circ}C$ for 30 days, respectively and changes of the physicochemical components of SPJ were investigated. The free amino acid compositions of pumpkin and SPJ occupied asparagine, aspartic acid, glutamine, arginine and serine in increasing order of abundance. Except SPJ heated for 3 hours, SPJ stored at 28$^{\circ}C$ had the most abundant free amino acids, followed by SPJ stored at 4$^{\circ}C$, and SPJ not stored. The fatty acid composition of pumpkin occupied behenic acid, erucic acid, palmitic acid, linoleic acid, heneicosanoic aicd, in order of abundance. When SPJ was heated over 3 hours, palmitic acid and linolenic acid decreased greatly. SPJ stored at 4$^{\circ}C$ and 28$^{\circ}C$ increased contents of saturated fatty acids such as behenic acid, palmitic acid than SPJ not stored. As SPJ was heated for a long time, carotenoid was mostly destroyed and the Hunter "L", "a" and "b" values of SPJ decreased. Among the mineral constituents of SPJ, Na and Ca were dominantly occupied. It was found that the range of the total visible cell count was 3~4CFU/ml from the SPJ which was heated for 3 hours and it increased by 1$\times$109CFU/ml when the SPJ was stored at 28$^{\circ}C$. It seems that the contamination by microorganism have occurred at packing process. In sensory evaluation, the SPJ which was heated for 5 hours had the highest scores in overall preference, sweet smell and sweetness.ce, sweet smell and sweetness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1027-1033
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• 1998

Stewed pumpkin juice(SPJ) has recently become popular as a health drink, and its consumption is growing rapidly. Well ripened pumpkin was heated in a pressure cooker and squeezed to an extract and then packed in retort pouches. The ingredient of ginger, onion, jujube and boxthorn was added to samples of SPJ in order to observe the effect on the composition of SPJ during production and storage at 28oC for 60 days. The level of the main mineral(K) in pumpkin varied when the ingredients were added. The pH of control SPJ showed more changes than the SPJs with ingredients added, and there was almost no change in the samples with boxthorn. During storage, titrable acidity decreased in all samples, and the SPJs with ginger and jujube showed relatively little change compared to the samples of control SPJ and SPJ with onion. As for soluble solid and reducting sugar, the SPJs with jujube and boxthorn showed the highest reading. For carotenoid, the SPJs with jujube, ginger, boxthorn and onion listed according to the amount of carotenoid contained more total carotenoid than the control SPJ. Most of the carotenoid in pumpkin and its extract was found to be carotene by HPLC and Chandler's method. Sensory evaluation of the SPJ samples with ingredients revealed preference for the taste of the SPJs with jujube, ginger and boxthorn in declining order of preference. The taste of SPJs with ingredients added was generally preferent over the control SPJ except the case of SPJ with onion.