Warm (20C) or cold (3C) broccoli florets (Brassica oleracea L., Italica Group) were sealed in bags of two types of nonperforated flexible polyvinylchloride film, TPM 87 or RMF 61, and kept at 5C for 7 days. Temperature of the warm florets cooled to 5C in ≈ 8 hours. Warm broccoli had 40% to 50% more CO2 and 25% to 30% less O2 than cold broccoli in packages of both film types 6 hours after sealing. After 48 hours, however, concentrations of CO2 in bags of cold and warm broccoli had reached a steady state of ≈ 14.5% in TPM 87 bags and 6% in RMF 61 bags. Concentrations of O2 were more variable. After 48 hours, O2 concentrations were ≈ 2% to 4% in TPM 87 bags and 5% to 10% in RMF 61 bags. Initially, warm florets were rated lower for color, turgidity, and general appearance than initially cold ones after 7 days at 5C. Objectionable off-odors were formed from florets held in TPM 87 packages that had O2concentrations of <1.5%.
Charles F. Forney and Roger E. Rij
Charles F. Forney, Roger E. Rij, Ricardo Denis-Arrue, and Joseph L. Smilanick
The potential use of vapor phase hydrogen peroxide (VPHP) to prevent decay caused by Botrytis cinerea Pers. ex Fr. in table grapes (Vitis vinifera L.) was investigated. `Thompson Seedless' and `Red Globe' grapes, inoculated with Botrytis cinerea spores, were placed in polyethylene bags and flushed for 10 minutes with VPHP generated from a 30% to 35% solution of liquid hydrogen peroxide at 40C. Immediately after treatment, bags were sealed and held at 10C. Vapor phase hydrogen peroxide significantly reduced the number of terminable Botrytis spores on grapes. The number of terminable spores on `Thompson Seedless' and `Red Globe' grapes had been reduced 81% and 62%, respectively, 24 hours following treatment. The incidence of decay on inoculated `Thompson Seedless' and `Red Globe' grapes was reduced 33% and 16%, respectively, after 8 days of storage at 10C compared with control fruit. Vapor phase hydrogen peroxide reduced the decay of noninoculated `Thompson Seedless' and `Red Globe' grapes 73% and 28%, respectively, after 12 days of storage at 10C. Treatment with VPHP did not affect grape color or soluble solids content.