OPTIMIZATION OF HMF FORMATION IN WHITE AND RED GRAPE JUICE CONCENTRATES STORED IN VARIOUS LAMINATED FILMS USING RESPONSE SURFACE METHODOLOGY

OpenAlex · İngilizce

ABSTRACT The effect of packaging materials on the formation of 5-hydroxymethyl 2-furfural (HMF) was investigated. Red and white grape juice concentrates at 70°Brix filled into pouches from three different packaging materials including polyethylene/polyamide (PE/PA), polyethyleneterephthalate/polyethylene (PET/PE) and polyethyleneterephthalate/aluminum/polyethylene (PET/Al/PE) were stored at 28 and 37C for 6 months. HMF, browning index (A420) and clarity (%T625) analyses were conducted by taking samples at 1th, 2nd, 3rd and 6th months during storage. The coefficient of determination, R2 values for HMF formation, A420 and %T625 were 1.00. Statistical analysis showed that packaging materials, grape juice concentrate, storage temperature and time were significantly (P < 0.0001) correlated to HMF, A420 and %T625. Based on response surface and contour plots, optimum conditions for HMF formation, A420 and %T625 were: (PET/A1/PE) packaging materials, storage temperature of 36.53C and storage time of 1.22 months for white grape juice concentration and (PET/A1/PE) packaging materials, storage temperature of 28.12C and storage time of 5.80 months for red grape juice concentration. PRACTICAL APPLICATIONS Results revealed that packaging materials, the colour of grape juice concentrate, storage time and temperature were significantly (P < 0.0001) correlated to HMF, browning index and clarity. Best packaging material was PET/AL/PE lamination among the ones tested. Temperature should be kept low during storage to obtain better quality. Red grape juice concentrates were wore sensitive to storage time and temperature than white ones. Increased storage temperature from 28C to 37C yielded more than ten-fold increase on average HMF content.