• Corrosion Science and Technology
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• 제4권2호
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• pp.51-55
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• 2005

The corrosion inhibitive effect of Poly (p-Anisidine) on iron in 1M HCl with various concentrations were studied by using electrochemical methods such as impedance measurements and polarization techniques. The inhibition efficiency (IE) of Poly (p- Anisidine) was compared with its monomer and it was observed that there is a remarkable increase for the polymer. Further, it is found that the value of IE increases with increasing concentrations for both monomer and polymer of p-Anisidine.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.264-264
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• 2017

Legumes are good sources of various nutrients. Among legumes, soybean and its flour are accessible foods to consumers. However, in case of soybean flour, there is a disadvantage of easily going rancid. Thus, this study aimed to investigate how the quality of soybean flour changes during storage according to the packaging materials and storage temperatures. The raw and roasted soybean flours were packed in two types of packaging, polyethylene (PE) and polypropylene (PP) film bags respectively, and stored at three different storage temperatures (4, 20, and $45^{\circ}C$) for 1 year. The acid value, conjugated diene value, peroxide value, p-anisidine value, thiobarbituric acid (TBA) value, lipoxygenase activity, and fatty acid content of raw and roasted soybean flours were measured at the point of starting storing, and after 1, 2, 4, 8, and 12 weeks of storage. The acid value of soybean flour was increased for 4 weeks and thereafter significantly decreased (p < 0.0001). The conjugated diene value was significantly increased after 4 weeks storage at $45^{\circ}C$ with PE and PP film bags (p < 0.0001). The peroxide value had no changes during 4 weeks storage at $45^{\circ}C$ with PE and PP film bags, and then those was dramatically increased after 8 weeks (p < 0.0001). The p-anisidine values in all of storage conditions were decreased after 4 weeks. Lipoxygenase activity was decreased at 12 weeks storage at $20^{\circ}C$ and $45^{\circ}C$ with PP film bags. Acid value had positive correlations with p-anisidine value (r = 0.30 and p < 0.0001) and lipoxygenase activity (r = 0.36 and p < 0.0001), and had negative correlations with conjugated diene value (r = -0.45 and p < 0.0001) and peroxide value (r = -0.25 and p < 0.001). Conjugated diene value had a high positive correlation with peroxide value (r = 0.76 and p < 0.0001), but that had a negative correlation with lipoxygenase activity (r = -0.51 and p < 0.0001). Peroxide value had negative correlations with p-anisidine value (r = -0.20 and p < 0.01) and TBA value (r = -0.15 and p < 0.05). The degree of reduction in fatty acid content of raw soybean flour was higher than the roasted soybean flour during the storage. Total fatty acid content had positive correlations with acid value (r = 0.45 and p < 0.0001) and p-anisidine value (r = 0.58 and p < 0.0001), but had a weak negative correlation with conjugated diene value (r = -0.19 and p < 0.01). This study showed how the rancidity of the raw and roasted soybean flours progressed during storage. Thus, our findings can be used as base data to do a further study of finding and developing more stable storage conditions of the soybean flour.

• 한국작물학회지
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• 제63권4호
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• pp.338-359
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• 2018

Soybean (Glycine max L.), a major part of Asian diet, is consumed primarily for its nutritional value. However, poor storage stability often leads to loss of nutritional value or deterioration in quality. This study focused on the storage stability of soy flour obtained from raw and roasted "Saedanbaek" soybeans packed in polyethylene (PE) and polypropylene (PPE) film bags that were stored at $4^{\circ}C$, $20^{\circ}C$ and $45^{\circ}C$ for 48 weeks. The early acid values (diene and p-anisidine) of raw soybean flour (RSF) at high temperature (HT) were higher than those at refrigerated temperature (RFT) and room temperature (RT) during 48 and 12 to 36 weeks, respectively. In the case of roasted soybean flour (ROSF), which was stored at RFT and RT, the acid and conjugated diene values gradually increased after 24 weeks. In RSF, the peroxide value increased since the beginning of the $24^{th}$ week. The p-anisidine value also increased during 12 to 36 weeks but was much lower than the values obtained from HT storage. As the peroxide values decreased, the p-anisidine values increased, indicating an inverse relationship. Lipoxygenase activity of ROSF at all storage conditions was lower than RSF. Several differences were observed between the packing materials used. This study could, therefore, provide useful information for the industrial use of soybean flour (SF).

• 분석과학
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• 제33권5호
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• pp.215-223
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• 2020

The objectives of the present study were to assess the oxidative stability of South Korean n-3 (omega-3 fatty acid) supplements carried out from 2018 to 2019 and evaluate the influence of product characteristics on oxidative safety. A total of 76 n-3 supplements were analysed for oxidation safety by four markers, including acid value (AV), primary oxidation (peroxide value, PV), secondary oxidation (p-anisidine value, pAV) and total oxidation value (TOTOX). Among the supplements tested, 5.3 %, 55.3 %, 28.9 % and 46.1 % exceeded the international voluntary recommended levels for AV, PV, pAV and TOTOX, respectively. Purity (%) of products, remainder of expiration date (suggested shelf life), package in press through package (PTP) and products with additives had statistically significant differences oxidation assessment levels (p < 0.05). In addition, n-3 group found in Algae oil had significantly lower AV levels than the group that did not, and product with Alaska pollack oil, had significantly higher pAV levels than without group (p < 0.05). The high oxidation status of South Korean n-3 products in the present study could not be considered a public health problem right now. However, the levels of oxidation may affect a lot the efficacy and safety of using n-3 supplements. Thus, current oxidation safety limits should be reestablished by regulatory bodies to ensure the safety and efficacy of n-3 supplements, so that the standards could be applied to the products available to consumers.

• 한국식품조리과학회지
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• 제33권3호
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• pp.275-284
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• 2017

Purpose: This study was performed to evaluate the effects of sannamul or herb extract addition to a soybean oil-in-water emulsion during photooxidation in the presence of chlorophyll. Methods: The emulsion mainly consisted of purified soybean oil and citric acid buffer (pH 4.0) at a weight ratio of 4 to 6, with chlorophyll a addition at 6 mg/kg. Ethanol extract of daraesoon, samnamul, basil, or peppermint was selectively added to the emulsion at 400 mg/kg, and emulsions in glass serum bottles were oxidized at $5^{\circ}C$ under 2,600 lux light for 48 hours. Lipid oxidation of the emulsions was evaluated based on determination of headspace oxygen content, peroxide value, and p-anisidine value. Pigments and antioxidants were also monitored. Results: The emulsion with added samnamul extract with high contents of polyphenols and low chlorophyll content showed lower oxygen consumption, peroxide values, and p-anisidine values, whereas basil and peppermint extracts with high chlorophyll contents increased photooxidation. Chlorophylls were degraded during photooxidation of the emulsions, and the degradation rate was highest in the emulsion with added samnamul extract. Conclusion: The high antioxidant activity of samnamul extract in the photooxidation of soybean oil-in-water emulsion could be due to low chlorophyll content, high concentrations of polyphenol compounds in the extract, as well as rapid degradation of chlorophylls during oxidation.

• 한국식품과학회지
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• 제52권1호
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• pp.46-53
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• 2020

Carrots were deep fat fried with sunflower oil (SO), palm oil (PO), and a blend of palm and sunflower oils (PSO with PO:SO as 2:8 or 4:6) at different temperatures (180 and 190℃) and lengths of time (0.5 to 2.5 min). The quality of deep fat fried carrots was determined by the moisture and fat content, color, conjugated dienoic acid (CDA), hydroperoxide, p-anisidine value, and fatty acid composition. The moisture content of fried carrots decreased with increasing frying time, while the fat content increased. The CDA and p-anisidine values of carrots fried with SO were higher than those fried with PO because of greater unsaturated fatty acids content in SO. PSO was a better choice than SO or PO for deep fat frying carrots in the aspects of oxidative stability and ratio of unsaturated to saturated fatty acids. These results indicate that the quality of deep fat fried carrots depends on the type of oil and frying temperature used, as well as the length of time.

• Food Science and Biotechnology
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• 제15권3호
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• pp.404-408
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• 2006

Feasibility of surface plasmon resonance (SPR) method to evaluate soybean frying oil quality was evaluated. Free fatty acid value, p-anisidine value, conjugated dienoic acid content, conjugated trienoic acid content, peroxide value, iodine value, total polar compound (TPC), ratio of unsaturated fatty acid to saturated fatty acid, refractive index, dielectric constant, smoking point, and L, a, and b of Hunter color system were selected as parameters related to conventional evaluation of soybean frying oil quality. SPR scale mapped with conventional quality parameters well described free fatty acid value, conjugated dienoic acid content, dielectric constant, TPC, and b of Hunter color system, as shown by correlation and linear regression analyses.

• 한국식품과학회지
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• 제39권2호
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• pp.133-137
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• 2007

유지의 산화안정도 측정을 위해 개발된 DPPH법의 최적화를 위해 시료의 양에 따른 유지의 산화변화를 분석하였고, 결정도니 조건을 사용하여 시중에서 튀김유로 사용되는 4종류 식용유지의 열산화안정성을 측정하였다. CDA와 p-AV는 산화반응이 진행될수록 증가하였으며 시료간의 상대적인 산화안정성 차이를 확인할 수 있었다. 반면에 DPPH법은 유지의 산화라디칼과의 반응성을 이용하며 흡광도의 증가와 감소를 반복하는 경향을 나타냈고 이로부터 유지산화라디칼의 변화를 측정 할 수 있었다. 또한 유지의 초기 전자 혹은 수소공여능을 확인할 수 있었고, DPPH 흡광도 증가를 통해 산화방지물질의 소진속도 및 산화라디칼의 생성속도를 계산할 수 있었으며, 산화방지물질의 소진시점을 결정할 수 있었다. 따라서 DPPH법을 기존의 산화도 측정방법과 병용한다면 유지의 산화도는 물론 산화반응 단계를 측정 할 수 있고, 산화안정성을 예측하는데 도움이 될 것으로 기대된다.

• 한국식품위생안전성학회지
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• 제34권5호
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• pp.480-488
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• 2019

오메가-3 제품의 안전성을 알아보기 위하여, 경기지역에 유통되는 20개의 fish oil과 algae oil을 원료로한 건강기능식품 오메가-3에 대하여 EPA와 DHA의 함량과 산화 정도를 조사하였다. 산가의 결과값은 0-2.9 mg/g으로 평균 및 표준편차는 $0.5{\pm}0.6$이며 CODEX/FAO의 기준 3.0 mg/g을 적용하였을 때 모두 적합하였으며, 과산화물가의 경우 2.6-14.1 meq/kg로 평균 및 표준준편차는 $5.5{\pm}2.9$이며, 기준 5.0 meq/kq을 적용하였을 때 20건 중 11건이 적합하고 9건이 기준을 초과하였다. 아니시딘가는 국제적인 기준을 20을 적용하였을 때 18건이 적합하였으며 2건이 기준을 초과하였다. 총 산화가는 기준 26을 적용하였을 때 16건이 적합하였으며 4건이 기준을 초과하였다. 오메가-3의 산화에 대한 안전성 확보를 위하여 새롭게 설정되어 3월부터 시행되고 있는 산가 및 과산화물가에 대한 기준 올해 11월 시행예정인 아니시딘가와 총산화가에 대한 시행은 매우 바람직하며 지속적인 감시를 통하여 산화로부터의 안전성 확보에 기여할 것으로 보인다.

• 산업식품공학
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• 제21권1호
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• pp.49-56
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• 2017

Vegetable seed oils (VSOs) have been extracted and used not only as ingredients in food and as sources of dietary lipids, but also as sources of nutraceuticals used to overcome the various oxidative stresses that contribute to the development of diseases, including cancer and other chronic conditions. The chemical compositions and oxidative stabilities of various VSOs were therefore investigated; samples were stored for 35 d, with each oil having been tested under $O_2$ exposure, sealed from $O_2$ exposure and sealed from $O_2$ exposure while containing $O_2$ scavengers. Oxidative stability was evaluated by peroxide value (POV), p-anisidine value (p-AnV), iodine value (IV), and thiobarbituric acid (TBA) value. Perilla seed and flaxseed oil were mostly composed of linolenic acid (45.5% and 59.7%, respectively), whereas pine seed oil was mostly composed of linoleic acid (48.3%). Meanwhile, camellia seed and olive oils contained 80% oleic acid, which correlated strongly with oxidative stability. The POV, p-AnV, and TBA values were the highest under $O_2$ exposure, and the lowest in the presence of $O_2$ scavengers. These results indicate that VOS oxidative stability depends not only on storage conditions, but on unsaturated fatty acid profiles as well.