F Human laboratory test of GABA rinse-free rice
The double-blind, placebo-controlled parallel-group comparative study was performed to evaluate the efficiency of GABA health function on factors such as blood-pressure lowering and stress relief. Rinse-free rice was used for the test rice to continuously intake; Hokkaido-produced “Yumepirika” brand in 2012 was used for the test rice. GABA rinse-free rice is for active control, and general rinse-free rice is for placebo. The intake amount of GABA per day by GABA rinse-free rice was set to about 17mg which is about four times the placebo. This test was set for 46 Japanese men and women (effective persons: 39) between 40 and 64 years old and having high blood pressure. These regularly took 150g-test rice (about 300g of cooked rice) per day over an eight-week period to verify the blood pressure lowering and anti-stress effects and to evaluate the availability. Also, neutral fat lowering, blood sugar level improvement, intestinal regulation and sleeping quality improvement were discussed as the sub effect to comprehensively evaluate the QOL improvement. As for the result, the blood pressure on awakening of the active control group was a significantly lower value (P<0.05) compared with placebo after an intake of between six and eight weeks, and after one week of finishing the test. The results showed that GABA lowers blood pressure. As for anti-stress effects - cortisol in the blood, which decreases according to decreased stress, exhibited a tendency to decrease (non-significant, 0.05<P<0.1) compared with placebo after an intake of eight weeks. For the visual analogue scale questionnaires, which included “peaceful” and “having anxiety”, the active control was significantly improved (p<0.05) compared with placebo after an intake of four weeks. It suggests the possibility of stress relief due to GABA. In other blood tests, adiponectin in the blood of active control exhibited a tendency to increase (0.05<P<0.1) after an intake of eight weeks, but GABA didn’t affect other blood components (plasma noradrenalin, blood sugar level and blood fat level) or composition. The above results conclude that GABA rinse-free rice is effective at preventing and improving high blood pressure and is expected to relieve the stress. GABA rinse-free rice can be cooked in the usual and is as tasty as regular milled rice. GABA rinse-free rice has the ability to become a popular functional food in Japan because rice is Japan’s staple diet. 82 | August 2017 - Milling and Grain
Figure 2: GABA Enriching System (5 tonne Type)
Table 2: GABA Enrichment Result Year, Variety
Nagano-produced Koshihikari in 2011
Hiroshimaproduced Hinohikari in 2012 Hokkaidoproduced Yumepirika in 2012 Ishikawa-produced Koshihikari in 2012
Ishikawa-produced Koshihikari in 2013
Hokkaidoproduced Nanatsuboshi in 2013
Sample
GABA (mg/100g.d.b)
GLU (mg/101g.d.b)
Conversion Rate (%)
Transfer Rate (%)
Brown rice
3.2
28.6
66.4
69.8
GABA brown rice
22.2
8.3
GABA white rice
16.9
8.6
GABA rinse-free rice
15.5
7.6 89.5
72.0
76.2
63.8
88.0
63.8
65.7
73.1
86.1
69.3
Brown rice
3.2
15.2
GABA brown rice
16.8
3.6
GABA white rice
13.1
3.2
GABA rinse-free rice
12.1
3.0
Brown rice
5.7
17.2
GABA brown rice
18.8
3.7
GABA white rice
13.2
3.4
GABA rinse-free rice
12.0
3.3
Brown rice
6.4
12.5
GABA brown rice
17.4
3.8 3.9
GABA white rice
11.8
GABA rinse-free rice
11.1
3.5
Brown rice
5.5
13.7
GABA brown rice
14.5
3.7
GABA white rice
10.8
4.4
GABA rinse-free rice
10.6
4.2
Brown rice
3.6
15.1
GABA brown rice
16.6
4.8
GABA white rice
12.5
4.4
GABA rinse-free rice
11.5
3.8
AVG.
78.6
68.6
Table 3: Comparison of Five Flavors Sample
Sweetness
Saltiness
Sourness
Bitterness
Umami
General rinse-free rice
2.44
1.21
1.13
1.12
1.95
GABA rinse-free rice
2.88
1.28
1.12
1.11
2.41