• Food Science and Biotechnology
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• v.16 no.4
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• pp.590-593
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• 2007

The textural properties of doughs mixed with L-ascorbic acid (AA), trypsin hydrolyzed gluten peptide (THGP), and a mixture of AA-THGP were investigated using texture analyzer under the fermentation of the full formula and the freezing process. The full formula dough (FFD) required a shorter mixing time than the flour and water formula dough (FWD). The maximum resistance (Rmax) values of both the unfrozen and frozen doughs were lower for the FFD. The effects of AA and THGP additions were not significant (p<0.01) in FFD, however, they were significant in FWD. The freezing effect was significant (p<0.0001) for FFD, indicating that yeast fermented dough was much more sensitive to damage from freezing, which subsequently affected dough strength. Additions of AA (p=0.0026) and THGP (p=0.0097) had a significant effect on the extensibility (E-value) of unfrozen FWD, where THGP increased and AA decreased the E-value. However, freezing did not significantly effect the extensibilities of FWD (p=0.64) or FFD (p=0.21). The area of FFD was lower than the area of FWD for both the unfrozen and frozen doughs. However, the frozen dough mixed with THGP alone had the largest area overall. The addition of additives did not result in significantly different (p<0.01) areas under the curve, except in the frozen FFD. Freezing caused a statistically significant difference in the area of FWD (p=0.0045).

• Food Science and Biotechnology
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• v.15 no.5
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• pp.805-813
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• 2006

The quality of frozen bread dough made with the milk proteins casein (C), whey (W), and the gums sodium alginate (A) and ${\kappa}$-carrageenan (K), was investigated to develop methods to suppress the deterioration of the frozen dough quality. The control had a lower dough volume than dough with additives during freeze-thaw cycles. In bread stored at $5^{\circ}C$, the moisture content of bread prepared with whey plus sodium alginate (WA) decreased less than that of the control. The control also had a lower specific loaf volume than breads made with added milk proteins and gums. The hardness of the control bread and bread made with casein plus sodium alginate (CA) and whey plus ${\kappa}$-carrageenan (WK) increased during freeze-thaw cycles, although that of the control increased more than the others. There was no significant difference in sensory preference among breads with and without milk proteins and gums. Addition of CA and WA improved the baking quality by reducing the deterioration of frozen dough and retarding the staling of bread.

• Korean journal of food and cookery science
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• v.9 no.3
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• pp.230-238
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• 1993

The objectives of this study were to provide the basic data for the consumer education and for the new product development by surveying housewives'demands concerning prepared frozen or refrigerated foods and by surveying industry's practices and opinions concerning new product development. 804 housewives and 14 manufacturing companies of prepared frozen or refrigerated foods were surveyed. Data from housewives were analyzed by using SPSS-X progrm in terms of $x^2$-test, one-way ANOVA, t-test. The results of study are summarized as follows : 1. Frozen dumpling, frozen meat, surimi, ham and sausage were identifed as the most frequently used food items by housewives. The mean storage period for either prepared frozen or refrigerated foods was less than 15 days. 2. Housewives with higher educational background showed the greater concerns in packing and sanitary conditions, convenience in cooking procedures and brand name of the product than their counterparts. 3. Most housewives'purchasing motive for prepared frozen or refrigerated foods was the convenience of the cooking procedures(71.1%). Among the member of family, children(72.8%) specially liked prepared frozen or refrigerated foods. 4. Housewives'demands for prepared frozen or refrigerated foods were 'price reduction'and 'nutrition fortification'. These were in accordance with the companys'opimons. 5. Most wanting new product developments from the housewives perspectives were beverages (37.7%), stir-fried menu items(36.1%), pan-fried menu items(34.0%), stewed menu items(30.3%) and soups(20.4%). In case of stew and soups, the industry did not have a plan to develop those menu items.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.772-782
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• 2013

A study is undertaken to examine the effects of the additional frozen blueberry powder and anthocyanin powder extracted from black beans to quality attributes of pound cakes. Frozen blueberry powder and anthocyanin powder extracted from black beans are being added to the flour at a ratio of 0.5, 1.5, 2.5, and 3.5% respectively. The antioxidant activity is highly correlated with the total phenolic and total flavonoids contents of frozen blueberry powder and anthocyanin powder extracted from black beans of pound cakes, respectively (r=0.8423, p<0.001 r=0.9449, p<0.001). The quality characteristics of the specific volumes decreased significantly with increasing substitution levels of frozen blueberry powder and anthocyanin powder extracted from black beans (p<0.01). The lightness significantly decreased with increasing frozen blueberry powder and anthocyanin powder extracted from black beans of pound cakes' crusts and crumbs (p<0.01). The hardness, chewiness and gumminess tend to reduce, while the cohesiveness increase in both powders. The consumer acceptability score for 0.5~3.5% of frozen blueberry powder and anthocyanin powder extracted from black beans pound cakes ranked significantly (p<0.01) higher than those of the other groups according to taste, flavor and overall preferences. These results show that frozen blueberry powder and anthocyanin powder extracted from the black beans are a good ingredient for increasing consumer acceptability and overall healthy.

• Food Engineering Progress
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• v.14 no.1
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• pp.14-20
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• 2010

The objective of the current study was to determine the cryoprotective effects of trehaolse on lactic acid bacteria in the frozen yoghurt during long-term frozen storage conditions. The frozen yoghurts were prepared using starter culture containing Lactobacillus bulgaricus and Streptococcus thermophilus, as well as trehalose and sorbitol as a cryoprotectant. The viable cell numbers of lactic acid bacteria in frozen yoghurt did not significantly decreased during six weeks frozen storage conditions. The MRS broth, which contains either trehalose or sorbitol, cultured with L. bulgaricus and/or S. thermophilus, and then the cultured medium was kept in the frozen condition for six weeks. The results indicated that lactic acid bacteria viability significantly increased with trehalose addition (2 and 5%) in the media compared to those of control and sorbitol supplement groups. The lactic acid bacteria viability in the yoghurts was examined on the effects of repeated freeze and thaw events. The freeze-thaw resistance of lactic acid bacteria significantly increased with trehalose supplement in the yoghurt. The major volatile aroma compounds (acetaldehyde, acetone, ethanol, diacetyl, and acetoin) in yoghurt were separated and indentified by headspace GC-FID analysis. Distinct flavor components and their ratios are known as important quality factors for yoghurt notes. Trehalose addition to the yoghurt was not influenced these factors during lactic acid fermentation. The results in this study demonstrated that trehalose potentially can be applicable as an effective cryoprotectant for lactic acid bacteria in the frozen yoghurt products.

• Food Science of Animal Resources
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• v.40 no.3
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• pp.350-361
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• 2020

Quality control of meat products is one of the main concerns of consumers, governmental control authorities, and retailers. The purpose of this study was to employ ribose-induced Maillard reaction in detection of meat adulteration and differentiation of fresh-chilled from frozen-thawed minced veal. The browning intensity was assessed through measuring the absorbance at 420 nm with a spectrophotometer as well as the direct analysis of the color and pH. The results showed that CIE b*, CIE a*, and A_420* values in the extract of fresh-chilled veal were significantly (p<0.05) higher than frozen-thawed samples. The extract of frozen meat samples stored at -18℃ became significantly darker and more yellowish compared to -4℃. The results showed that the A_420* value in the frozen-thawed veal stored at -4℃ and -18℃ was reduced by approximately 17.22±3.53% and 11.68±2.49%, respectively, compared with fresh-chilled veal. The findings also showed that the storage temperature of minced veal and the heating time in this reaction had a significant effect on all tested variables (p<0.0001). The proposed method can be considered as an easy, quick, and inexpensive test for differentiating between the fresh-chilled and frozen-thawed minced veal.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.509-512
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• 2011

To study the effect of freezing rate on the quality of freeze-dried rice porridge, freeze-dried rice porridge products were prepared with rice porridge pre-frozen at three different temperatures of -20, -40, and -70$^{\circ}C$. The porridge properties such as microstructure, mechanical properties, textural properties, and rehydration rate were determined. Scanning electron microscopy images indicated that fewer air cells were obtained with a larger size of freeze-dried rice porridge frozen at -20$^{\circ}C$ compared with that frozen at -40 and -70$^{\circ}C$. In contrast, quick frozen products at -70$^{\circ}C$ had more dense texture with higher mechanical strength, whereas slow frozen products exhibited higher rehydration rates than those of quick frozen products. In conclusion, the proper choice of pre-freezing temperature plays a decisive role when preparing freeze-dried rice porridge with optimum quality and convenience.

• Journal of the Korean Society of Food Culture
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• v.18 no.2
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• pp.105-110
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• 2003

This study was conducted to investigate the effect of freezing methods, slow freezing at $-20^{\circ}C$ and rapid freezing at $-70^{\circ}C$, on physical properties of Chinese cabbage in frozen Kimchi during storage at $-20^{\circ}C$. Elasticity of midrib of Chinese cabbage in frozen Kimchi was decreased until 15 days and did not changed thereafter during storage at $-20^{\circ}C$. Hardness of that was not changed during storage. Those results of elasticity and hardness of slow frozen sample are similar to rapid frozen sample. By the morphological observation through transmission electron microscope, more of cellular structure of Chinese cabbage in slow frozen was destructed than that of rapid frozen sample. Drip loss was more in slow frozen sample than that in rapid one.

• Food Science and Preservation
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• v.20 no.3
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• pp.296-303
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• 2013

This study was conducted to assess the possibility of preserving frozen vegetables (Aster scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion) for a long period and of using them after such storage by measuring changes in quality due to their preservation. Various freshly harvested vegetables were blanched under optimal conditions (that were determined in a preliminary experiment), quick-frozen at $-40^{\circ}C$ for 24 h, and stored at $-20^{\circ}C$. The change in the chromaticity of the frozen A. scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion did not vary. The hardness of the frozen A. scaber, green pumpkin, Chinese cabbage and Welsh onion did not change during the preservation period, whereas the hardness of the cotyledon and hypocotyl of the soybean sprouts significantly increased on the sixth month of their storage. The total bacterial counts of the A. scaber during the preservation period remained constant at $10^3$ CFU/g, whereas those of soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion decreased slightly to $10^2$ CFU/g. Coliform was not detected in any of the samples. The sensory evaluation showed that the preservation period that was used in this study did not significantly affect the marketability of the frozen vegetables. Therefore, it was considered that A. scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion can be safely preserved by freeze-storing them for up to 12 months.

• Food Science of Animal Resources
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• v.40 no.3
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• pp.444-460
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• 2020

This study was conducted to investigate the effects of freezing and storage temperature (-18℃, -50℃, and -60℃) on the physicochemical properties of pork neck and chicken leg meat in home-scale deep freezers. Pork neck was cut into a thickness of 3 cm (9×9×3 cm, 150 g), individually packed in air-containing packages, and stored at different temperature (-18℃, -50℃, and -60℃) for 6 months. Chicken leg meats were prepared (10 cm long, weighing 70 g) and packed in the same manner. Frozen samples were thawed at 2℃. Physicochemical properties such as thawing loss, cooking loss, water-holding capacity, color, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances (TBARS) were evaluated. The samples frozen by deep freezing (-60℃) was favorable with respect to thawing loss, color, and VBN. Samples frozen at -60℃ had lower values of thawing loss and VBN than those frozen at -18℃ for all storage periods (p<0.05). Color parameters were more similar to those of fresh meat than to those of samples frozen at -18℃ for 6 months. The TBARS of all samples were below 0.3 mg malondialdehyde/kg, thereby indicating oxidative stability of lipids. Consequently, deep freezing at -60℃ may be acceptable for maintaining the quality of fresh pork neck and chicken leg meat for 6 months without deterioration.