• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.9-14
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• 1997

The effect of freezing, thawing and blanching on the change of extractable pigment content of purple sweet potato (PSP) was investigated. Freezing at $-5^{\circ}C$ was more effective than freezing at $-20^{\circ}C\;or\;-40^{\circ}C$, and rapid thawing methods such as microwave heating or hat air blast heating were effective than slow thawing methods such as thawing at $4^{\circ}C\;or\;20^{\circ}C$. Inactivation of enzymes, which cause pigment destruction during thawing, by blanching before freezing was necessary to obtain the highest possible amount of extractable pigment from PSP. Microwave blanching for $3{\sim}4$ min or hot air blanching for $10{\sim}15$ min were effective in extracting pigment from PSP.

• Food Science and Preservation
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• v.5 no.4
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• pp.320-325
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• 1998

Effects of blanching and salting for the pretreatment during frozen storage condition were investigated and optimized the salting condition on the activities of peroxidase and lipoxygenase, the stability of vitamin C and color, moisture content and hardness in immatured soybean. Before frozen storage, pretreatment processing is necessary to extend the shelf-life of vegetables. Salting condition of 2% for 180min treatment led to maximum inactivation of both lipoxygenase and peroxidase while blanching can more inactivate for lipoxygenase. Salting at 2% for 180min resulted in the highest amount of vitamin C remaining in the immatured soybeans after 6 months storage. The color of the immatured soybeans were severely changed after 6 months storage, while the color of salted soybeans at 3% and 180min treatment was similar to fresh products. Moisture content and hardness were reduced with addition of salt.

• Journal of the Korean Society of Food Culture
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• v.36 no.5
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• pp.512-521
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• 2021

This study investigated the quality characteristics of sweet pumpkin after blanching. Sweet pumpkins were blanched in distilled water, 2% citric acid and 2% NaCl water at 100℃ for 3 min. The cooking loss of sweet pumpkin in the blanching groups was lower than that in the control group, and greenness and yellowness in the blanching groups were higher than those in the control group (p<0.001). Total polyphenol content (TPC) of sweet pumpkin increased after blanching (p<0.05), and TPC true retention (TR) was measured with the highest NB. CON and NB were significantly higher in ?-carotene content (p<0.001). Lutein content in the blanching treatment groups was lower than that in the control group, but NB was the highest between the blanching groups (p<0.001). DPPH and ABTS⁺ radical scavenging activity assays revealed higher antioxidant activity in the NB groups among the blanching groups (p<0.001). The CON was 2.44 log colony-forming unit (CFU)/ g in the total bacterial count, but there were no microorganisms in the blanching groups. In conclusion, blanching with the addition of 2% NaCl can inhibit the growth of microorganisms and improve TR and antioxidant activities in sweet pumpkin.

• Korean journal of food and cookery science
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• v.11 no.2
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• pp.98-103
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• 1995

The effect of blanching time, blanching water and power settings of microwave oven on the minerals retention in spinach and broccoli were investigated. The vegetables were blanched for 60, 120 and 180 sec, with water 0ml, 50ml and 100ml every 100 g of raw material at two different power settings (700w, 400w). The retention of minerals(Ca,K,Mg,Cu,Fe,Na,p) in spinach and broccoli were higher at the 400w power than 700w power level, regardless of blanching time. At the high power, the retention of minerals in spinach and broccoli were reduced remarkably as the blanching time increased. The reason for this is that the increasing power level results in greater water coming ou from the vegetable. Also, minerals in vegetable as coming out with this water loss in proportion to the blanching time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.281-285
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• 1998

For the purpose of improving the qualities of carrot, spinach and cooked rice, the effects of food height(0mm: H0, 5mm: H5, 10mm: H10, 15mm: H15) for microware blanching and reheating on physicochemical properties were investigated. In carrot blanching, color values of each treatment were not different, and cutting forces of microware blanching carrots were decreased as carrot height increased. In spinach blanching, the shape of orignal form was changed as height increased. In cooked rice reheating, H10 had the highest overall acceptance score. Physicochemical properties were changed by food hight of microwave blanching and reheating on food.

• Korean journal of food and cookery science
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• v.11 no.4
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• pp.337-341
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• 1995

The effect of time and amount of water by conventional blanching method on the retention minerals in spinach and broccoli was investigated. The vegetables were blanched for 1, 2, 3 and 4 minutes, with 150 $m\ell$, 300 $m\ell$, 450 $m\ell$ of water for every 100 g of raw material. Blanching of spinach showed that Na was reduced remarkably after 2 minute of blanching, the others (K, Fe, Ca, Mg, P, Cu) were gradually decreased as the blanching time increased. Blanching of broccoli showed that the content of minerals were reduced remarkably after 1 minute of blanching. The longer blanching time further reduced the content of minerals. The retention of minerals (Na, K, Fe, Ca, Mg, P, Cu) in spinach and broccoli was reduced gradually as the blanching water increased. The retention rate of minerals were 12.7％ of Na, 37.4％ of K, 37.1％ of Fe, 43.9％ of Ca, 39.0％ of Mg, 53.5％ of P, 56.2％ of Cu in spinach and 21.0％ of Na, 41.3％ of K, 57.8％ of Fe, 38.8％ of Ca, 51.5％ of Mg, 57.7％ of P, 44.4％ of Cu in broccoli for 4 min, with water 450$m\ell$ every 100g of raw material.

• Journal of the Korean Society of Food Culture
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• v.16 no.4
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• pp.388-397
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• 2001

Wild edible plants are consumed as raw and/or processed. Analytical data for raw biologically functional compounds were relatively well established. The changes on functional compounds during processing are, however, not well studied. This study was carried out to investigate the change of the quality of wild edible plants, Pimpinella brachycarpa(Chamnamul) at various conditions. Samples were blanched at the salt concentration of 0%, 1% or 2% for 1, 2, and 3 minutes each. The biologically active compounds, vitamin C, ${\beta}-carotene$, chlorophyll, flavonoids, polyphenols and minerals were analyzed. The concentration of vitamin C in Chamnamul decreased as blanching time increased. Beta-carotene in Chamnamul showed high concentration when Chamnamul was treated under longer blanching time. Higher salt concentration of blanching water, however, resulted in the increased concentration of ${\beta}-carotene$ in the blanched Chamnamul. Higher salt concentration of blanching water also reduced the loss of total flavonoids and total polyphenols from the blanched Chamnamul. The change of colors in the blanching water seemed to be corresponding to those of total flavonoids and total polyphenols concentrations in the blanching water.

• Food Engineering Progress
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• v.23 no.1
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• pp.69-75
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• 2019

This study investigated the effects of blanching conditions on the quality characteristics of burdock, lotus root, and garlic scape. The selected plants were blanched at varying temperatures (70-100℃) for 1-5 min, and moisture content, shear force, color, and total microbial count were analyzed. Burdock exhibited browning discoloration when it was blanched at a relatively low temperature (70-80℃). In addition, thermal tenderization of burdock was not evident in the blanching conditions adopted in this study. Blanching affected the tenderness and moisture content of lotus root without deteriorative discoloration. In particular, low temperature blanching (80℃) was favorable to blanching lotus root. Alternately, thermal tenderization of garlic scape was possible by blanching at 80-100℃ for 3-5 min, while discoloration of the blanched garlic scape dominated at high-temperature blanching (100℃). Consequently, the result indicated that low temperature for a long time (80℃ and 3-5 min) provided a better blanching condition for lotus root and garlic scape than high temperature applied at a short time (100℃ and 1-3 min).

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.246-253
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• 2012

In this study, we determined the optimum blanching conditions for pretreatment of Aster scaber prior to freezing to ensure its long, safe preservation as a fine cooking ingredient. Frozen-thawed A. scaber did not significantly differ between blanching groups, but the blanched group showed significantly higher Hunter L, a, and b values than the un-blanched group (p<0.05). Higher temperatures and longer treatment times increased softness; hardness did not significantly differ between the blanched and un-blanched groups of frozen-thawed A. scaber (p<0.05). Total bacterial counts and the presence of coliforms seemed to decline with blanching treatments, but treatment temperature and time did not influence this reduction. Over 95% of peroxidase activity was inactivated by blanching treatment but increased slightly after thawing. The sensory evaluation of the frozen-thawed A. scaber by test group showed the A. scaber blanched at $90^{\circ}C$ for 3 min to be the most highly preferred (p<0.05).

• Korean journal of food and cookery science
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• v.8 no.4
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• pp.411-419
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• 1992

Retention of ascorbic acid in vegetables as influenced by various blanching methods was measured and the effects of blanching time, amount of water added, and with or without lid on the retention were compared. It was found that blanching with small amount of water and without lid generally retained the higher activity of ascorbic acid. Although steam blanching showed the highest retention of the vitamin, the longer heating time was needed to blanch the vegetables. Blanching by microwave oven has revealed that addition of small amount of water did not affect the retention. From the scoring difference test for texture of blanched spinach, the samples which were indicated as best in texture by the 8-panel members have retained 73~96% of ascorbic acid and samples blanched by microwave oven for 60 seconds showed highest retention.