Nutritional values of raw and cooked ‘calçots’ (Allium cepa L. resprouts), an expanding crop

Abstract

BACKGROUND ‘Calçot’ is the Catalan name for the immature floral stems of second‐year onion resprouts of the Blanca Tardana de Lleida (BTL) landrace. Highly appreciated for their sensory attributes, these resprouts are typically consumed after roasting on an open fire. Now new preparations are appearing, helping to expand the market for ‘calçots’. This study aimed (i) to compare the nutritional and sensory characteristics of BTL ‘calçots’ versus other onion varieties; (ii) to analyze the effects of cooking and / or in vitro gastrointestinal digestion on the nutritional properties of ‘calçots’; and (iii) to determine the influence of the environment on the antioxidant properties of ‘calçots’. RESULTS The nutritional and sensory characteristics of both raw and cooked ‘calçots’ differed between varieties, with the exception of some minerals. Flavonoid content decreased by 85% during cooking, and total phenolic content decreased by 30%. By contrast, antioxidant activity increased after cooking. Most traits had a nonlinear response to heating, and differences between varieties generally decreased after cooking. Location also had a strong effect on antioxidant activity. In vitro digestion of cooked ‘calçots’ sharply decreased antioxidant activity after the intestinal phase. The only significant genotypic correlation between sensory and nutritional quality was the correlation between sweetness and ash content (R = −0.97). CONCLUSION Cooked BTL ‘calçots’ are within the limits of the onion domain for nutritional properties, and the variability reported for onion bulbs is also present in resprouts. The effects of the environment, cooking, and in vitro digestion clearly overlap the genetic effects. © 2019 Society of Chemical Industry

Comparative effect of environment on morphological, biochemical and phytochemical analysis of onion cultivated at high and low altitudes

“…Further, Galdón's and co-workers (2009) demonstrated role of various factors especially, environment, type of cultivar, agronomic practices, stage of maturation, and storage conditions in affecting the bioactive compound enrichment of onions. In addition, studies have also suggested that post-harvesting processes i.e., processing and storage, can also alter the bioactive compounds concentration in onions consequently, impacting their bioavailability and bioe cacy (Sans et al 2019).…”

Onion (Allium cepa L.) bioactives: Chemistry, pharmacotherapeutic functions, and industrial applications

“…Nevertheless, postharvest operations, such as processing and storage, can alter the concentration of bioactive compounds of onion, which consequently affect their bioavailability and efficacy (Hithamani et al., 2017; Sans et al., 2019; Zudaire et al., 2017). Various investigations reported the effects of storage time, as well as temperature, packaging, and freeze‐drying on the bioactive compounds (Majid & Nanda, 2017; Petropoulos et al., 2017; Zudaire et al., 2017).…”