Abstrato

Quality attributes of French fries as affected by different coatings, frozen storage and frying conditions

Kizito KF, Abdel-Aal MH, Ragab MH, Youssef MM*

Potato strips treated with different coatings (Carboxymethyl cellulose (CMC), pectin, agar and chitosan) at concentrations of 1 and 2% then fried for various durations (5, 7, 9, 11 and 13 minutes) were investigated for organoleptic and other quality parameters. Strips were submerged in coating solutions for 5 seconds prior deep fat frying. Frying for 11 and 13 minutes gave the most significantly accepted fries while all coating treated strips obtained lower sensory quality scores and the concentrations used did not significantly affect sensory parameters of strips (p<0.05). Coatings reduced the amount of oil absorbed by strips by 12.93% (pectin), 11.71% (CMC), 8.28% (chitosan) and 5.25% (agar). Coating treatments and concentration significantly improved moisture retention of strips (p<0.05). Strips treated with hydrocolloids at 1% and fried for 11 minutes revealed that texture and yellowness (b*) values were not significantly different from the control strips. Lightness (L*) values of treated strips were similar to the control strips except chitosan treated strips (p<0.05). Redness (a*) values of all coated strips were not significantly different from the control strips except agar coated strips. In another study, potato strips were semi-fried at 170 ± 5°C for 2 minutes followed by quick air blast freezing at -32°C for 20 min and stored at -18°C for 6 months. The effect of frozen storage duration on quality parameters was monitored every month. Data revealed that peroxide values (PV) initially increased and later decreased with elongation of storage duration. Free fatty acid (FFA), thiobarbituric acid (TBA) and p -anisidine ( p -AV) values significantly increased with storage duration (p<0.05). Total oxidation (totox) values increased with storage duration. The CMC coating treatment did not significantly lower PV, FFA and TBA values while p -AV values were significantly lowered during frozen storage (p<0.05).