본 연구는 반응표면분석법(RSM)을 이용하여 대사증후군 개선을 위한 뽕잎·오디·누에의 최적 혼합 비율을 도출하였다. 뽕잎·오디·누에의 최적 혼합 비율 도출을 위해 대사증후군 관련 생리활성 지표로 항산화, 항당뇨, 항고혈압 활성을 측정하여 활용하였다. 또한 도출된 최적 비율의 뽕잎·오디·누에 혼합분말을 양갱에 첨가하여 대사증후군 개선식품을 개발하고자 하였다.
항산화 활성이 최대로 발현된 뽕잎·오디·누에의 혼합 비율은 뽕잎(A)이 2.9298, 오디(B)가 0.2963, 누에(C)가 2.9530이었다. 이때 total polyphenol 함량은 188.78 TAE mg/g, total flavonoid 함량은 92.22 QE mg/g, DPPH radical 소거능은 84.96%, ABTS radical 소거능은 57.53%로 예측되었다.
항당뇨 활성이 최대로 발현된 뽕잎·오디·누에의 혼합 비율은 뽕잎(A)이 0.8132, 오디(B)가 0.0003, 누에(C)가 2.9999이었다. 이때 DNJ 함량은 420.44 mg/100 g, α-glucosidase 저해 활성은 69.74%로 예측되었다.
항고혈압 활성이 최대로 발현된 뽕잎·오디·누에의 혼합 비율은 뽕잎(A)이 2.9998, 오디(B)가 0.0127, 누에(C)가 3이었다. 이때 칼륨 함량은 1974.37 mg/100 g, ACE 저해 활성은 75.40%로 예측되었다.
항산화와 항당뇨 활성이 함께 최대로 발현된 뽕잎·오디·누에의 혼합 비율은 뽕잎(A)이 2.5130, 오디(B)가 0.1016, 누에(C)가 2.9407이었다. 이때 total polyphenol 함량은 184.28 TAE mg/g, total flavonoid 함량은 95.12 QE mg/g, DPPH radical 소거능은 84.76%, ABTS radical 소거능은 57.53%, DNJ 함량은 413.15 mg/100 g, α-glucosidase 저해 활성은 64.90%로 예측되었다.
항산화와 항고혈압 활성이 함께 최대로 발현된 뽕잎·오디·누에의 혼합 비율은 뽕잎(A)이 2.8308, 오디(B)가 0.1336, 누에(C)가 3이었다. 이때 total polyphenol 함량은 189.18 TAE mg/g, total flavonoid 함량은 95.13 QE mg/g, DPPH radical 소거능은 84.40%, ABTS radical 소거능은 58.63%, potassium 함량은 1934.51 mg/100 g, ACE 저해 활성은 74.65%로 예측되었다.
항당뇨와 항고혈압 활성이 함께 최대로 발현된 뽕잎·오디·누에 혼합 비율은 뽕잎(A)이 2.2406, 오디(B)가 0.0007, 누에(C)가 2.9979이었다. 이때 DNJ 함량은 420.31 mg/100 g, α-glucosidase 저해 활성은 66.28%, potassium 함량은 1861.10 mg/100 g, ACE 저해 활성은 75.47%로 예측되었다.
항산화·항당뇨·항고혈압 활성이 함께 최대로 발현된 뽕잎·오디·누에의 최적 혼합 비율은 뽕잎(A)이 2.6422, 오디(B)가 0.0524, 누에(C)가 2.9999이었다. 이때 total polyphenol 함량은 187.04 mg TAE/g, total flavonoid 함량 95.39 mg QE/g, DPPH radical 소거능 84.46%, ABTS radical 소거능 59.65%, DNJ 함량 438.47 mg/g, α-glucosidase 저해 활성 63.46%, potassium 함량 1901.60 mg/100 g, ACE 저해 활성은 75.43%로 예측되었다.
항산화·항당뇨·항고혈압 활성이 함께 최대로 발현된 최적 비율의 뽕잎·오디·누에 혼합분말을 첨가하여 제조한 양갱의 total polyphenol 함량은 31.67 TAE mg/g, total flavonoid 함량은 20.14 QE mg/g, DPPH radical 소거능은 54.43%, ABTS radical 소거능은 49.41%, α-glucosidase 저해 활성은 68.75%, ACE 저해 활성은 67.78%로 나타나 최적 비율의 뽕잎·오디·누에 혼합분말의 생리활성 효과가 양갱 첨가시에도 우수하게 발현되었다.
본 연구를 통해 뽕잎, 오디, 누에의 대사증후군 관련 생리활성 지표(항산화, 항당뇨, 항고혈압 활성)에 대한 우수성을 확인할 수 있었고, 각각의 지표에 대한 최적 혼합 비율과 생리활성이 최대로 발현될 수 있는 최적 혼합 비율도 도출되었다. 도출된 뽕잎·오디·누에의 최적 비율 혼합분말을 첨가하여 제조한 양갱 역시 생리활성의 우수함이 확인되어 대사증후군 개선에 도움이 될 수 있을 것으로 생각된다.
또한 본 연구는 주로 단일 소재의 생리활성 평가 후 식품에 첨가하여 품질평가를 진행한 연구와는 달리 RSM에 의한 실험설계로 세 가지 소재(뽕잎, 오디, 누에)간의 항산화·항당뇨·항고혈압 활성이 함께 최대로 발현될 수 있는 최적 혼합 비율을 도출하였다.
대사증후군 관련 생리활성 지표에는 본 연구에서 활용한 항산화, 항당뇨, 항고혈압 활성 외에도 다른 지표들이 있고, 도출된 일부 최적 비율 혼합분말의 경우 단일 소재의 효과보다 활성 효과가 낮은 경우도 있었다. 하지만 본 연구는 뽕잎, 오디, 누에 세 가지 소재 간의 시너지 효과를 확인함으로써 대사증후군 관련 생리활성 지표에 대한 세 가지 소재의 최적 혼합 비율을 구한 첫 번째 시도라는데 그 의의가 있겠다.
따라서 본 연구 결과를 바탕으로 뽕잎, 오디, 누에 세 가지 소재의 시너지 효과에 대한 기전 연구를 진행한다면 과학적인 근거 자료를 더 다양하게 제시할 수 있을 것으로 생각된다. 그리고 향후 이 같은 혼합분말의 시너지 효과를 극대화 할 수 있는 연구가 더 많이 이루어지길 기대한다.

In this study, we obtained the optimal mixing ratio of mulberry leaves, mulberry fruits and silkworms for the improvement of the metabolic syndrome by using the response surface method(RSM). Antioxidant, antidiabetic and antihypertensive activities were measured and used as an indicator of metabolic syndrome related physiological activity in order to derive the optimal mixing ratio of mulberry leaves, mulberry fruits and silkworm. We also aimed to develop a functional food for improving the metabolic syndrome by adding the mixture of the determined optimal mixing ratios of mulberry leaves, mulberry fruits and silkworms when preparing Yanggaeng.
The optimum mixing ratio of mulberry leaves, mulberry fruits and silkworms with the greatest antioxidant activities was as follows: 2.9298 of mulberry leaves(A): 0.2963 of mulberry fruits(B): 2.9530 of silkworms(C). At this time, it was predicted that total polyphenol content was 188.78 TAE mg/g, total flavonoid content was 92.22 QE mg/g, DPPH radical scavenging activity was 84.96%, and ABTS radical scavenging activity was estimated to be 57.53%.
The optimal mixing ratio of mulberry leaves, mulberry fruits and silkworms with the greatest antidiabetic activities was as follows: 0.8132 of mulberry leaves(A), 0.0003 of mulberry fruits(B), 2.9999 of silkworms(C). At this time, it was predicted that the DNJ content was estimated to be 420.44 mg/100 g, and α-glucosidase inhibitory activity was estimated to be 69.74%. The optimal mixing ratio of mulberry leaves, mulberry fruits and silkworms with the greatest antihypertensive activities was as follows: 2.9998 of mulberry leaves(A), 0.0127 of mulberry fruits(B), 3 of silkworms (C). At this time, it was predicted that the potassium content was estimated to be 1974.37 mg/100 g, and ACE inhibitory activity was estimated to be 75.40%.
The optimal mixing ratio of mulberry leaves, mulberry fruits and silkworms with the greatest antioxidant and antidiabetic activities was as follows: 2.5103 of mulberry leaves(A), 0.1016 of mulberry fruits(B), 2.9407 of silkworms(C). At this time, it was predicted that the total polyphenol content was 184.28 TAE mg/g, the total flavonoid content was 95.12 QE mg/g, the DPPH radical scavenging activity was 84.76%, the ABTS radical scavenging activity was 57.53%, the DNJ content was 413.15 mg/100 g, and α-glucosidase inhibitory activity was estimated to be 64.90%.
The optimum mixing ratio of mulberry leaves, mulberry fruits and silkworms with the greatest antioxidant and antihypertensive activities was as follows: 2.8308 of mulberry leaves(A), 0.1336 of mulberry fruits(B), 3 of silkworms(C). At this time, it was predicted that the total polyphenol content was estimated to be 189.18 TAE mg/g, the total flavonoid content was 95.13 QE mg/g, the DPPH radical scavenging activity was 84.40%, the ABTS radical scavenging activity was 58.63%, the potassium content was 1934.51 mg/100 g, and the ACE inhibitory activity was 74.65%.
The optimal mixing ratio of mulberry leaves, mulberry fruits and silkworms with the greatest antidiabetic and antihypertensive activities was as follows: 2.2406 of mulberry leaves(A), 0.0007 of mulberry fruits(B), 2.9979 of silkworms(C). At this time, it was predicted that the DNJ content was 420.31 mg/100 g, the α-glucosidase inhibitory activity was 66.28%, the potassium content was 1861.10 mg/100 g, and the ACE inhibitory activity was 75.47%.
The optimal mixing ratio of mulberry leaves, mulberry fruits and silkworms with the greatest antioxidant, antidiabetic and antihypertensive activities was as follows: 2.6422 of mulberry leaves(A), 0.0524 of mulberry fruits(B), 2.9999 of silkworms(C). At this time, it was predicted that the total polyphenol content was estimated to be 187.04 TAE mg/g, total flavonoid content 95.39　QE　mg/g, DPPH radical scavenging activity 84.46%, ABTS radical scavenging activity 59.65%, DNJ content 438.47 mg/g, α-glucosidase inhibitory activity 63.46%, potassium content 1901.60 mg/100 g, and ACE inhibitory activity was estimated to be 75.43%.
The total polyphenol content and the total flavonoid content of Yanggaeng prepared by adding mulberry leaves, mulberry fruits, and silkworm powder mixed with the optimal ratio of antioxidant, antidiabetic and antihypertensive activity were 31.67 TAE mg/g and 20.14 QE mg/g, respectively. And the DPPH radical scavenging activity was 54.43%, the ABTS radical scavenging activity was 49.41%, the α-glucosidase inhibitory activity was 68.75%, and the ACE inhibitory activity was 67.78%. Thus, the biological activity of the mixture of the optimal mixing ratio was found to be excellent when preparing Yanggaeng.
In this study, we identified the significant effect of the mulberry leaves, mulberry fruits and silkworms on the metabolic syndrome-related biological activity indices(antioxidant activity, antidiabetic activity and antihypertensive activity). We also presented the optimal ratios for each index and the optimal mixing ratio for maximizing the biological activity effects. We also confirmed that the Yanggaeng which was developed by adding the optimal ratio of mulberry leaves, mulberry fruits, and silkworm showed excellent biological activities. Therefore, the developed Yanggaeng is expected to improve the metabolic syndrome.
In addition, unlike the studies in which the evaluation of biological activity of a single material was performed and the quality evaluation was carried out, we determined the metabolic syndrome-related biological activity indices(antioxidant activity, antidiabetic activity, and antihypertensive activity) by selecting three materials that are good for improvement of metabolic syndrome in this study. Then we determined the optimum mixing ratio which could maximize the synergistic effect of the three materials through RSM.
There are other indicators besides the antioxidant, antidiabetic and antihypertensive activity used in this study. And in some cases, the activity effect of the optimal mix powder was lower than that of the single material. However, this study is the first attempt to determine the optimal mixing ratio of the three materials for the metabolic syndrome related physiological activity index by confirming the synergy between mulberry leaves, mulberry fruits, and silkworm.
Therefore, based on the results of this study, it would be possible to present more scientific data on the synergistic effects of mulberry leaves, mulberry fruits, and silkworm. And we expect that more research will be done to maximize the synergy effect of such mixed powders in the future.