• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.220-226
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• 2006

Soybean sprout is a traditional food and its market circulation as packed in a transparent film is increasing. To characterize the off-flavor produced from film-packed soybean sprouts, harvested soybean sprouts were stored at different temperature and oxygen conditions, and time-series changes in heads pace $O_2,\;CO_2$, ethanol (EtOH) concentrations as well as sensory off-flavor levels were measured. Lower temperature resulted in lower consumption of $O_2$, lower production of EtOH and less off-flavor. No off-flavors could be detected when atmospheric $O_2$ concentration was maintained over 4%, while alcoholic-flavor and off-flavor were initiated when $O_2$ decreased down to 2% and 1%, respectively. Under low $O_2$ conditions alcoholic-flavor following EtOH production preceeded prior to sensory off-flavor detection. Various aldehydes and fatty acids such as nonylaldehyde, decylaldehyde and stearic acid were identified by GC/MS from film-packed sprouts producing off-flavors. In conclusion to suppress off-flavor, soybean sprouts should be packed in a film which can control $O_2$ concentration over 2% and stored at low temperature around $4^{\circ}C$.

• Journal of the Korean Society of Food Culture
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• v.25 no.3
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• pp.324-333
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• 2010

Off-flavor in foods and in raw materials is quite concerning, as it could signify deeper-rooted problems. Methods of reduction of "off-flavors" in traditional food such as Cheonggukjan and Kimchi, and in raw materials of soybean paste were studied by means of a literature review. It was found that the major components of "off-flavor" were due to butyric acid, valeric acid, alkylpyrazines, ammonia, and sulfides for Cheonggukjang, and for Kimchi were sulfur containing components such as methyl allylsulfide, dimethyl disulfide, diallyl disulfide, methyl allyl trisulfide, methyl 2-propenyldisulfide, dipropenyldisulfide. There is a demand for a scientific and systematic approach in overcoming the "off-flavor" problem. Nutritional aspects and safety should be considered. Several methods have been attempted, such as masking, binding, improving cooking process, inhibiting rancidity, and controlling the growth of micro-organism. Methods of masking were the most frequently ones used for the reduction of "off-flavor", and in some cases, othertechniques were additionally applied. The masking method would be useful in the reduction of "off-flavor" in traditional Korean foods, i.e. Cheonggukjang, Kimchi, as well as in new product development.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.222-228
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• 2007

This study was conducted to investigate the minimization of off-flavor occurrence and the maintenance of high quality in modified atmosphere packaged Pleurotus ostreatus during the storage. There are 4 treatments used to preserve high quality and for deodorization of MAP mushroom: Artemisia princeps, Artemisia capillaries, green tea and activated charcoal. The mushrooms were packed in polyethylene film with each treatment and were stored at 5 and $20^{circ}C$. No difference was observed in weight loss, $CO_2\;and\;O_2$ concentration, or color of mushrooms packed with or without treatment. However, the principal component analysis (PCA), electronic nose, revealed differences in off-flavor occurrence between control (MAP mushroom without treatment) and treatment groups at $5^{\circ}C$. This result suggested that Artemisia princeps and Artemisia capillaries was masking the off-flavor in MAP mushroom because the unique flavor of them was strongly revealed and green tea and activated charcoal might have a role of removing the off-flavor by adsorbing ethanol and acetaldehyde, which is known to cause off-flavor. The sensory test showed that Artemisia princeps and Artemisia capillaries dough treatment inhibited microbial growth.

• Korean Journal of Food Science and Technology
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• v.13 no.1
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• pp.53-56
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• 1981

Several tests were conducted to study lipoxygenase activity and off-flavor developement in frozen sweet corn. Fresh corn contained about 60% of total lipoxygenase activity in the germ section. When non-blanched frozen sweet corn was stored at $-10^{\circ}F$, it developed off-flavor and most significant changes in the flavor profile of off-flavored sweet corn was $4{\sim}5$ times higher hexanal peaks. The high hexanal peaks observed in the sterilized sweet corn with added lipoxygenase, alone and in combination with other enzymes, suggested the fact that high hexanal peaks in off-flavored sweet corn could be due to an oxidative reaction of lionleic acid (and other unsaturated fatty acids) catalyzed by lipoxygenase. Based on lipoxygenase activity and linoleic acid content in sweet corn, this reaction occur most heavily in the germ section of sweet corn. There was a significant relationship between flavor score of frozen stored corn-on-the-cob and hexanal peak in the germ section of corn-on-the-cob. This result indicated that hexanal peak could be used as an objective index of off-flavor development in frozen sweet corn.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.353-358
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• 2003

Volatile compounds of porcine liver were collected by simultaneous steam distillation and extraction and steam distillation under reduced pressure. Volatiles were analyzed by gas chromatography (GC) and GC-mass spectrometry. Key aroma compounds of off-flavor in porcine liver were characterized using GC-olfactometry technique. Concentrates of cooked porcine liver had odor of a typical liver, fishy, and metallic off-flavor. Aroma concentrates showed over 90 peaks, of which 69 compounds were positively and/or tentatively identified. 1-Octen-3-one, 1-hexanol, (E)-2-nonenal, (Z)-4-decenal, (E,E)-2,4-heptadienal and (E,E)-2,4-decadienal were newly identified in this study. These compounds seem to be produced from unsaturated fatty acids of porcine liver by oxidation. 1-Octen-3-one (metallic), 1-hexanol (metallic) and (E,E)-2,4-heptadienal(fishy) have been implicated in fishy and metallic off-flavor in cooked porcine liver.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.425-430
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• 2015

The objective of the study was to investigate the off-flavor generated from PET water bottles and their caps by using a mass spectrometry-based electronic nose. The ion fragment data obtained from the electronic nose were used for discriminant function analysis (DFA). In the case of increased concentrations of the contamination of water, the off-flavor pattern depended on the discriminant function second score instead of the discriminant function first score. To identify the cause of off-flavor in polyethylene terephthalate (PET) bottled water, the PET bottle and its cap were analyzed by DFA. The results showed that the cap generated more volatile compounds than the bottle or mineral water did. The substances causing the off-flavor were predicted to be 2,4-di-tert-butylphenol (2,4-DTBP), nonanal, and decanal when the main peak of the mass spectrum was compared with the major ion fragments of the electronic nose. Thus, using this method, we could determine whether the PET water bottle was contaminated and whether the off-flavor resulted from contamination of the bottle cap.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.4
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• pp.257-262
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• 2007

Squid viscera oil was investigated by pretreatment method for enhancing the commercial value. Transeterification was performed to reduce rancidity of the oil, off-flavor was removed by using activated carbon adsorption. Analysis using ATD (Automatic Thermal Desorber) and GC/MG shows the efficacy of off-flavor removement. The rates of Transesterification employing inorganic catalyst and biocatalyst were tested, respectively. With stepwise addition of ethanol, the most efficiency of the reaction was achieved by inorganic catalyst. The efficiency of the reaction was estimated by acid value corresponding to rancidity of reaction product.

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.173-180
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• 2022

There are a number of methods to evaluate the quality of squid. However, when purchasing the fish, consumers and retails rely only on the sensory test and flavor in the field. Therefore, this study was aimed to prove relationship between scientific indicator and sensory test. Total viable cell count (TVC), viable cell count of Pseudomonas spp., pH and volatile basic nitrogen (VBN) were selected as scientific indicators and mesured during the storage of squid at different temperature. The squid was storaged at 3 different temperature (5℃, 15℃, 20℃). Off flavor determination time was measured by R-index, and kinetic modeling was conducted. Activation energies of off-flavor determination time, TVC, Pseudomonas spp, VBN, and pH were 51.210 kJ/mol, 42.88 kJ/mol, 50.283 kJ/mol, 72.594 kJ/mol and 41.99 kJ/mol respectively. Activation energy of off-flavor determination time was approximated to viable cell count of Pseudomonas spp., TVC, pH and VBN as an order. Especially, viable cell count of Pseudomonas spp. had best match of the activation energy. Therefore, it was judged that indicator of off-flavor determine time was viable cell count of Pseudomonas spp..

• Journal of the East Asian Society of Dietary Life
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• v.7 no.2
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• pp.211-220
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• 1997

This study was investigated about preparation of ice at home and developing points which met consumer's demand that was focused on auto icemaker. According to purposive quota sampling method, residences in Seoul and Kyunggi-do area were selected and interviewed by trained interviewer at August 1995. The results were as follows: 66.3% of respondent usually prepared ice in ice-making container of refrigerator and used when they needed. 85% of them used ice in summer and seldomly used in other seasons. Boiling water with barley was major drinking water(45.6%), and broiled or purified tap water was used to make ice(38.6%) commonly. Numbers of ice-making container were two(66.0%). Above 50% of respondents replied that they felt off-flavor in ice usually. After felt off-flavor, 54.7% of respondent threw away the ice, some of them used off-flavored ice after treatment to washing with water. 64.9% of respondents thought that the origins of off-flavor was the flavor of refrigerator itself. The consumer's expectation of developing points were as follows. The most priority of developing points was to make ice quickly, the next was to develop auto ice maker and ice storage container, to make different size of ice. Less expected points were to make more clear ice and large volume of ice in one time. The recognition about auto ice maker was slightly low(35% of respondents), but 67% of them wanted to develop auto ice maker.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.728-732
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• 1998

The purpose of this study was to identify off-flavor compounds in sea mustard and rice syrup sold in the markets. Naphthalenes such as naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, 2,6-dimethylnaphthalene, 1,5-dimethylnaphthalene, 1,8-dimethylnaphthalene, 2,7-dimethylnaphthalene, 1,4,6-trimethylnaphthalene, 2,3,6-trimethylnaphthalene etc., were present in sea mustard, while free fatty acids such as butanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid and 2-furanmethanol, 2-furancarboxaldehyde etc. in rice syrup. The former (naphthalenes) have been supposed to be contaminents from paint of ship and the latter (free fatty acids) derived from deteriorated rice for saccharification. From the results of the samples studied, formation of their off-flavor compounds seems to be related with the condition of storage, the process of production and circulation in the markets.