Retardation of rancidity in deep‐fried instant noodles (ramyon)

Abstract

AbstractThe storage stability of instant fried noodles (ramyon) was determined by accelerated aging at 63 C with organoleptic evaluation of the onset of rancidity. Three methods of extending the shelf‐life of ramyon were examined: (a) addition of 200 ppm antioxidant, butylated hydroxyanisole (BHA), t‐butylhydroquinone (TBHQ), or a polymeric antioxidant (Poly‐A) to the frying (palm) oil; (b) coating the inner surface of the polyethylene package with TBHQ equivalent to 200, 500 and 1000 ppm based on the oil in the ramyon; and (c) addition of a mixture of 200 ppm TBHQ and 200 or 500 ppm disodium ethylene‐diaminetetraacetate (EDTA) to the frying oil. When the antioxidants were added to the oil, BHA and Poly‐A approximately doubled while TBHQ tripled the shelf‐life of ramyon. The mixture of TBHQ (200 ppm) and disodium EDTA (500 ppm) in the frying oil quintupled the shelf‐life. The inner surface application of TBHQ (200 ppm) extended shelf‐life twice that of an equal amount of TBHQ in the frying oil. Rancid off‐flavors developed slowest in noodles with aw 0.3. Hexanal concentration in ramyon was a good indicator of the development of oxidative rancidity. Organoleptic evaluation showed the flavor of ramyon was objectionable when hexanal concentration reached 3.5 ppm based on the weight of ramyon (as is). The relative effectiveness of antioxidants in preventing off‐flavor in ramyon could be determined from the hexanal concentration in stored ramyon.