Fruit and Vegetable Wash Has No Effect on Postharvest Decay But May Increase Lenticel Damage in ‘Empire’ Apples

According to the Canada Food guide, eating a variety of fresh fruits and vegetables will keep us healthy. Research has shown that eating lots of fresh produce reduces the risk of some cancers and other diseases. It is suggested to wash the fresh produce before eating and in some commercial facilities the produce is washed with Fruit and Vegetable Wash (FVW) before shipping to the retailers.

In a preliminary study, we tested the effect of FVW on postharvest diseases and lenticel damage in ‘Empire’ apples. Prior to this experiment, apples had been stored for 6 months in standard controlled atmosphere storage (~ 2.5% O₂ + 2% CO₂ at 2^oC). Half of the fruit were artificially wounded using a nail-like probe, to ensure the uniformity of the size and depth of the wound, and the remaining half were not wounded.

There were four main treatments: 1) no wound, plus FVW, 2) no wound, FVW, and then wax, 3) wound, plus FVW, and 4) wound, FVW, and then wax. Each of these main treatments had 3 sub-treatments, representing 0.1%, 0.2% and 0.3% FVW. All the apples were dipped in the FVW for 1 minute and then rinsed in water for 2 minutes. In addition, there were water only and no dip controls. The fruit received wax after the water rinse, when scheduled. All 12 treatments were replicated three times. Each replicate consisted of 40 fruit. After the treatments, fruit were incubated for 1 week in cold storage at 0^oC and then the apples were moved to 20^oC for an additional week. Decay and lenticel damage were recorded after 1 week at 20^oC.

Results indicate that <10% of blue mold/decay was observed in the apples that were not wounded with or without FVW, and 99-100% of the wounded fruit with or without FVW had blue mold/decay. Therefore, FVW had no significant effect on storage decay in ‘Empire’ apples.

Lenticel damage was found on some of the fruit, with the higher concentrations of FVW causing increased incidence. Apples treated with 0.1% FVW had 2.5% lenticel damage incidence, whereas 5.4-6.3% of fruit treated with 0.2 or 0.3% FVW exhibited lenticel damage. It is important to note that these data are from ‘Empire’ apples that were stored in CA storage for 6 months. The effect of FVW on other cultivars and ‘Empire’ from other storage regimes and durations still needs to be tested.