The antioxidant effects by pre-treatment of Hutgae fruit water and ethanol (30°, Soju) extract on refrigerated eels were analyzed. The antioxidant activities were measured through DPPH and ABTS scavenging effect, values of acidity, peroxide, carbonyl, and TBA. The peroxide prevention effects of linoleic acid and eel oil were also assessed. Regarding DPPH radical scavenging, Hutgae ethanol extract presented higher scavenging effects than vitamin C 5 mM solution (p<0.05). The eel’s peroxidation degree was measured through 21 days of refrigeration after cleaning and immersion into the extract solution for one hour. Upon measuring the values of four different peroxide indicators, those of eels pre-treated with Hutgae extracts were lower than those of eels untreated. The POV of Hutgae ethanol extract, vitamin C 5 mM, and the control was 11.1, 11.3, 15.5 meq/kg, respectively. Hutgae ethanol extract showed higher antioxidant activities in TBA value, and carbonyl value than other samples. In linoleic acid or eel oil, Hutgae extract was as superiorly effective in preventing peroxide generation of refrigerated eels as vitamin C 10 mM solution. In conclusion, pre-application of Hutgae water and ethanol (30°, Soju) extract on eels was proved to be competent in stopping peroxidation of eel in refrigeration.

The objective of this study was to investigate the sensory quality attributes for the development of soy sauce containing an extract of the fruit of Hovenia dulcis Thunb (Hutgae), also known as liver function improvement and hangover removal. Aqueous extracts of Hutgae fruit and Hutgae fruit-soy sauce were used for determining the sensory evaluation. The intensity of the sweet smell and taste was predominated in the Hutgae fruit extract (p<0.05). Various seasoning items, such as apples, pears, dried figs, Korean bramble (Bokbunja), citron (Yuza) and sun-dried hot pepper (Taeyangcho), were used to determine the suitable type of seasoned soy sauce with the Hutgae fruit extract. In the sensory analysis, the highest overall preference (acceptance score 5) was obtained from the pear extract added to soy sauce with the Hutgae fruit. The overall preference of Yuza (score 4.9) and Taeyangcho (score 4.5) extracts also very well-matched the seasoning items for soy sauce with the Hutgae fruit extract. There was no difference among the extract mixtures of multi-seasoning items added to soy sauce with the Hutgae fruit extract. As more pear extract was added, a higher overall preference was obtained. On the other hand, as the more Yuza extract was added, the higher flavor intensity without the change of the overall preference was obtained. The overall preference of soy sauce with the pear- Yuza-Taeyangcho extract mixture was not different between with or without the Hutgae fruit extract. However, the overall preference (score 5.6) was significantly higher in the pear extract added to soy sauce with the Hutgae fruit extract compared with the pear extract added to soy sauce without the Hutgae fruit extract (score 4.8). These results suggest that soy sauce with the Hutgae fruit-pear extract mixture may be useful as a functional seasoning for various salad dressings.

Home-made soy sauces with or without Hovenia dulcis Thunb (Hutgae) originated from different parts such as fruits, stems, and twigs were prepared according to the Korean traditional procedure. Soy sauces supplemented with Hutgae were evaluated for their activities of 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) and alcohol dehydrogenase (ADH), free amino acid profiles, and sensory quality. All soy sauce types containing Hutgae had a strong DPPH activity as compared to the general type of soy sauce without Hutgae (GSC). Among Hutgae groups, DPPH activities of soy sauce supplemented with Hutgae stems was higher than that of soy sauces with either Hutgae fruits or twigs. ADH activities of soy sauces with Hutgae ranged from 14% to 55%, thus indicating that the functional activity of Hutgae was not altered during soy sauce preparations. Total free amino acid content of GSC was 295.5 ㎎%, and that of soy sauce with Hutgae fruits (346.8 ㎎%) was the highest when compared to Hutgae stems (272.3 ㎎%) and Hutgae twigs (225.6 ㎎%). In amino acid profiles, aspartate, arginine, histidine, and lysine levels were higher in soy sauces with Hutgae compared to GSC, whereas isoleucine, leucine, and phenylalanine levels were lower. Particularly, high levels of aspartate, glutamate, threonine, and lysine were presented in Hutgae twigs, whereas for Hutgae fruits and Hutgae stems, the levels of serine, glycine and arginine, and proline and methionine were high, respectively. According to sensory evaluations, Hutgae stems were preferred than GSC, due to the lower offensive smell and higher umami tastes. These findings demonstrate that soy sauce with Hutgae stems has potential protective effects against hangovers, improves the taste, and implies a possible functional ingredient.

The objective of this study was to investigate free amino acid composition, antioxidant activity, alcohol dehydrogenase activity and the sensory quality attributes for the development of functional soy sauce using Hutgae (Hovenia dulcis Thunb) fruit, which is well-known for improving liver function and alleviating various negative physiological effects following heavy consumption of alcoholic beverages. Soy sauces adding six types of extract from Hutgae fruit (HF) were prepared (SSH1: HF 20%, SSH2: HF 10%, SSH3: HF 20%/40 days NaCl extract, SSH4: HF 20%/20 days NaCl extract, SSH5: HF 20% water bath extract, SSH6: freeze-drying powder from HF 20% aqueous extract), compared with soy sauce using the conventional method. These soy sauces were used for determining alcohol dehydrogenase activity by NADH absorbance, the antioxidant effect by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and sensory evaluation by sensory scaling. Total free amino acid contents for most samples were in the range of 327.3 to 375.5 ㎎%, and then, aspartic acid and glutamic acid content of SSH1 and SSH5 were higher than that of others. DPPH radical scavenging activity was shown to be the highest in SSH4, also SSH1, SSH5 and SSF6 were shown to be higher than the control group. Alcohol dehydrogenase activity was shown to be the highest in SSH5. In sensory evaluation, the highest intensity of roast smell was observed in SSH4 while sweet taste was shown to be the highest in SSH5, and SSH3 and SSH5 revealed higher overall acceptability. From these results, Hutgae fruit soy sauces demonstrated antioxidant activity and alcohol dehydrogenase activity. In conclusion, soy sauces containing the water bath extract of Hutgae fruit may be used as a functional seasoning.

발효에 의한 헛개열매의 기능성 상승 정도를 검토하고자, 헛개열매열수추출물을 발효시킨 후 급성 및 만성 알코올 투여 간손상 동물모델을 통하여 체중감량 억제, 알코올 분해 및 간기능 개선 효능을 검증하였다. 급성 알코올 투여 동물모델에서 헛개열매발효군(ET-FHWE)은 알코올대조군(ET)에 비하여 혈청 알코올 농도가 유의적으로 감소되었고, 특히 알코올 투여 3시간 후의 알코올 농도는 헛개열매추출액발효물에 의해 46.1%, 헛개열매열수추출물에 의해 19.1% 감소된 것으로 나타났다. 또한 알코올 투여에 의해 증가된 혈청 아세트알데하이드 농도는 헛개열매추출액발효물에 의해 알코올 투여 3시간 후에는 48.7%, 5시간 후에는 39%로 알코올대조군(ET)보다 유의적으로 감소하였고, 이는 헛개열매열수추출물은 발효에 의해 알코올 및 아세트알데하이드 분해능이 증가하는 것으로 사료되었다. 만성 알코올 투여 간손상 동물모델 실험에서 알코올 투여에 의해 상승된 혈청 알코올 농도는 헛개열매열수추출물과 헛개열매추출액발효물 투여에 의해 각각 31%, 41% 유의적으로 감소하였다. 혈청 아세트알데하이드 농도와 γ-GTP 활성도는 헛개열매열수추출물과 헛개열매추출액발효물 투여에 의해 알코올대조군(ET)보다 유의적으로 감소되었으며, 장기간 알코올 투여에 의한 체중 감소 억제 및 간조직 지질수준의 유의적 감소를 나타내었다. 또한 헛개열매추출액발효물은 장기간의 알코올 투여로 인해 감소된 혈당을 유의적으로 증가시키는 것으로 나타났다. 본 연구 결과, 급성 알코올 투여 동물모델에서 헛개열매열수추출물은 발효에 의해 알코올 및 아세트알데하이드 분해능이 증진되었고, 만성알코올 투여 모델을 통한 실험에서는 발효에 의해 헛개열매의 간기능 개선효능이 유지됨과 동시에 일부 효능(혈청 지질 및 혈당 수준 개선능)은 증가하는 것으로 나타났다. 따라서 헛개열매추출액발효물은 급성 및 만성 알코올성 간손상 억제에 있어서 헛개열매열수추출물보다 더욱 강력한 기능성 물질로 활용될 수 있을 것으로 기대된다.

국내에서 자생하고 있는 헛개나무 잎과 과병의 각종 화학성분을 분석한 결과 일반성분 중 잎의 경우 조단백질, 과병의 경우 총당이 높게 나타났으며, 무기성분은 잎과 과병에서 K, Ca, Mg, Na 및 Mn 순으로 나타났다. 비타민 C 함량은 잎의 경우 4.8 mg%, 과병은 3.8 mg%로 나타났으며, 유리당은 잎에서 fructose가 1.31%, 과병에서는 sucrose가 8.83%로 가장 높게 나타났다. 유기산은 잎과 과병에서 malic aci