Health-Promoting Compounds in Broccoli as Influenced by Refrigerated Transport and Retail Sale Period

Abstract

Total aliphatic and indole glucosinolates, phenolic compounds (flavonoids and hydroxycinnamoyl derivatives), and vitamin C contents were evaluated in freshly harvested broccoli (Brassica oleracea L., var. italica, cv. Marathon) inflorescences. These were film-wrapped and stored for 7 days at 1 °C to simulate a maximum period of commercial transport and distribution. After cold storage, inflorescences were kept for 3 days at 15 °C to simulate a retail sale period. For wrapping, low-density polyethylene (LDPE) of 11 μm thickness was used. Gas composition was about 17% O2 and 2% CO2 during cold storage and about 16% O2 and 3−4% CO2 during shelf life within packages. The predominant glucosinolates were 4-methylsulfinylbutyl-glucosinolate (glucoraphanin), 3-indolylmethyl-glucosinolate (glucobrassicin), and 1-methoxy-3-indolylmethyl-glucosinolate (neoglucobrassicin). The predominant hydroxycinnamoyl derivatives were identified as 1,2,2‘-trisinapoylgentiobiose, 1,2-diferuloylgentiobiose, 1,2‘-disinapoyl-2-feruloylgentiobiose, and 3-O-caffeoyl-quinic (neochlorogenic acid). Results showed major losses at the end of both periods, in comparison with broccoli at harvest. Thus, the respective losses, at the end of cold storage and retail periods, were 71−80% of total glucosinolates, 62−59% of total flavonoids, 51−44% of sinapic acid derivatives, and 73−74% caffeoyl-quinic acid derivatives. Slight differences in all compound concentrations between storage and retail sale periods were detected. Distribution and retail periods had minimal effects on vitamin C. Weight loss was monitored at the end of both periods.