การผลิตฟิล์มบริโภคได้จากผงบุกผสมสารสกัดจากสมุนไพรไทยเพื่อยืดอายุการเก็บรักษามะม่วงพันธุ์น้ำดอกไม้ เบอร์ 4 / จุพาพันธุ์ รัตนนิล = Production of edible film from konjac powder incorporated with Thai medicinal plants extracts for extending shelf life of mangoes CV. Nam Dok Mai # 4
Colletotrichum gloeosporioides is the cause of anthracnose disease on mango CV. Nam Dok Mai after harvesting. This research was aimed to study the effect of using crude extracts of Thai medicinal plants including Boesenbergia pandurata, Alpinia galanga and Zingiber officinal on prevention of anthracnose disease. Both water and ethanolic extracts of zingiberaceous presented the growth inhibition of C. gloeosporioides, especially the ethanolic extracts of B. pandurata and A. galanga showed the outstanding antifungal activity against C. gloeosporioides. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of plant extracts were 2,500 µg/ml. Ethanolic extract of B. pandurata and A. galanga at the concentration ranged from 2,500 - 30,000 µg/ml were incorporated in Konjac solution to form edible film. The antifungal activity of the edible film solution and edible film were tested. It was found that Konjac film solution incorporated with A. galanga and B. pandurata extracts required 10,000 µg/ml as a minimum concentration to inhibit C. gloeosporioides. However, for Konjac film, the minimum concentration of B. pandurata and A. galanga extracts to inhibit C. gloeosporioides were 10,000 and 20,000 µg/ml, respectively. Mechanical properties of Konjac film incorporated with ethanolic B. pandurata and A. galanga extracts were determined. Tensile Strength and Elongation value of incorporated film were lower than the one without B. pandurata and A. galanga extracts. WVTR value of incorporated Konjac film was also lower than the one without B. pandurata and A. galanga extracts which reveals that it has better ability to prevent water vapour. The use of Konjac solution incorporated with A. galangal extract at 30,000 µg/ml for extending shelf life of mangoes storage temperature 13±1°C and relative humidity 90-95% was studied. The results showed that the coating delayed the change of mangoes’s quality. Both Konjac solution and Konjac solution incorporated with A. galanga could significantly retard weight loss, softening, changes of peel color, total solution solid and titratable actidity, and decreases anthracnose disease. But the coating made off-flavor. Konjac film incorporated with A. galanga can retard anthracnose disease when compare with control during 30 days storage.