Preservation of apple slices using ascorbic acid and 4-hexylresorcinol

The use of sulphites for the prevention of browning on fruits and vegetables is banned in the USA. The possible alternative use of ascorbic acid (AA), 4-hexylresorcinol (HR), and a mixture of both on apple slices was studied taking quality retention as a function of storage time as compared with similar products treated with sulphites. The mixture of ascorbic acid and 4-hexylresorcinol (AH) significantly inhibited the browning of vacuum packaged apple slices for up to 8 weeks during storage at 0.5 degrees C (p less than or equal to 0.001). Browning inhibition by AH was comparable to that achieved by sulphite and stronger than that of ascorbic acid (AA). In addition AH did not bleach the fruit tissue and therefore the colour of AH treated fruits was closer to the fresh apple pieces than those treated with sulphite. AH also reduced the total viable microbial counts by more than 10-fold as compared with AA treated and control apple pieces. AH treated apple pieces had a slightly firmer texture than the control and there were no adverse effects on the soluble solids and titratable acidity of the fruit. The evidence suggests that AH is a promising anti-browning formula for minimally processed apples.