Free amino acid composition in primary and secondary inflorescences of 11 broccoli (Brassica oleracea var italica) cultivars and its variation between growing seasons

Abstract

Eleven broccoli cultivars were grown in the ®eld in spring/summer (April±July) and summer/ winter (September±January). Free amino acid composition was determined by HPLC in primary and secondary in¯orescences separately. A total of 17 amino acids were identi®ed: L-valine (Val). The major amino acid was L-glutamine, which represented on average between 39.5% (in cvs Durango and Green Valiant) and 55.5% (in cv Shogun) of the total amino acid content among cultivars, followed by L-glutamic acid with a variation between 12.1% (in cv Shogun) and 17.4% (in cv Marathon). A few amino acids represented less than 1% each (Gly, Leu, Met, Phen, Thr, Trp and Tyr). For most of the amino acids there were signi®cant differences between cultivars, whilst only a few amino acids showed signi®cant variations between in¯orescences. Season also induced signi®cant differences in the content of most of the identi®ed amino acids. The cultivar with the highest total free amino acid content (323.9 mmol kg À1 DW) on average of both seasons (391.3 in spring/summer and 256.4 in summer/winter) was Shogun, whilst the others were above the minimum of 177.3 mmol kg À1 DW found in cv SK3. There was a general tendency for higher total amino acids levels in spring/summer than in summer/winter, but it was clear that this effect was dependent on the cultivar. # 2000 Society of Chemical Industry Keywords: free amino acids; essential amino acids; broccoli; Brassica oleracea var italica; growth seasons; nutritive quality; primary in¯orescences; secondary in¯orescences INTRODUCTION Broccoli (Brassica oleracea var italica) is a plant of the Brassicaceae which in the past decade has received special attention owing to recognised human health bene®ts when its in¯orescences are part of the diet (see review by Rosa et al 1 ). The high levels of vitamin C, dietary ®bre and antioxidants and the presence in the in¯orescences of 4-methylsulphinylbutyl glucosinolate (glucoraphanin), a precursor of 4-methylsulphinylbutyl isothiocyanate or sulphoraphane, a potent inducer of enzymes that protect against chemical carcinogens, are the major attributes for such interest 2±6 and the support for recommendations of higher broccoli consumption.

Protein, amino acid, ash and mineral contents in Brassica spp. grown in Northwest Spain

“…(2000) observed that the leaves contain more amino acids than the stems. Gomes & Rosa (2000) and Oliveira et al. (2008) showed that the distribution of amino acids is not similar in internal and external leaves in Brassica spp.…”

“…These differences could be in part because of various factors such as genotype, environmental factors, growing conditions, maturity and part of the plant analysed (Kmiecik et al. , 1999; Gomes & Rosa, 2000; Ishida et al. , 2000; Lisiewska et al.…”

Comparison of nutritional composition of farmed pufferfish muscles among Fugu obscurus, Fugu flavidus and Fugu rubripes

“…. F. rubripes had the highest ratio of TUAA/TAA among the three pufferfish, which indicated that the living environment, such as salinity, might affect the nutritional composition of farmed pufferfish, including flavor (Gomes and Rosa, 2000), while it has been suggested that free amino acids may influence fish flavor (Hwang and Chen, 2000). The influence of amino acid composition on flavor and variations in amino acid profile caused for example by varying rearing temperatures upon final product quality clearly represents an area deserved of future research (Gonzá lez et al, 2006).…”

Effect of cooking on free amino acid and mineral profiles of sweet chestnut (Castanea sativaMill.)

“…Extraction was performed by sequential extraction with first 70% and then 90% v/v methanol in combination with a heating plate and a homogeniser [1,7]. After each extraction, the samples were centrifuged.…”

“…Free amino acids are implicated in secondary plant metabolism and in the production of compounds which directly or indirectly play an important role in the plant-environment interaction and in human health [1]. Additionally, amino acids directly contribute to the flavour and colour of food induced during thermal reactions in the stages of production, processing and storage of food [2].…”