Comparative Phytonutrient Analysis of Broccoli By-Products: The Potentials for Broccoli By-Product Utilization

Abstract

The phytonutrient concentrations of broccoli (Brassica oleracea var. italica) florets, stems, and leaves were compared to evaluate the value of stem and leaf by-products as a source of valuable nutrients. Primary metabolites, including amino acids, organic acids, and sugars, as well as glucosinolates, carotenoids, chlorophylls, vitamins E and K, essential mineral elements, total phenolic content, antioxidant activity, and expression of glucosinolate biosynthesis and hydrolysis genes were quantified from the different broccoli tissues. Broccoli florets had higher concentrations of amino acids, glucoraphanin, and neoglucobrassicin compared to other tissues, whereas leaves were higher in carotenoids, chlorophylls, vitamins E and K, total phenolic content, and antioxidant activity. Leaves were also good sources of calcium and manganese compared to other tissues. Stems had the lowest nitrile formation from glucosinolate. Each tissue exhibited specific core gene expression profiles supporting glucosinolate metabolism, with different gene homologs expressed in florets, stems, and leaves, which suggests that tissue-specific pathways function to support primary and secondary metabolic pathways in broccoli. This comprehensive nutrient and bioactive compound profile represents a useful resource for the evaluation of broccoli by-product utilization in the human diet, and as feedstocks for bioactive compounds for industry.

Functional Ingredients From Brassicaceae Species: Overview and Perspectives

“…This valorization process is especially relevant in popular crops like broccoli, which represents 34% of total cruciferous production in the world, according to the Food and Agriculture Organization Corporate Statistical Database (FAOSTAT, 2017, www.fao.org/faostat/es/). Broccoli floret, the edible part, represents just 15% of the total vegetable, producing 85% (stems and leaves) of valuable by-products [83]. Other Brassica species by-products have been studied as sources of bioactive compounds, among them red radish or kale, among others [84].…”

New food ingredients from broccoli by‐products: physical, chemical and technological properties

“…Broccoli ( Brassica oleracea L. var. italica ) contains many health‐promoting phytonutrient components including glucosinolates, isothiocyanate, flavonoids and polyphenolic compounds (Liu et al ., ). The world‐wide consumption of broccoli has increased significantly over recent years.…”

“…The florets are harvested for the consumer market, while edible stems and leaves comprising more than 70% of the broccoli plant, are discarded (Zhang et al ., ). The stems and leaves contain valuable phytonutrients, vitamins and essential minerals with many health‐promoting activities and may be potentially be used as food ingredients or supplements in the functional food or pharmaceutical industry (Kumar & Andy, ; Ares et al ., ; Hwang & Lim, ; Liu et al ., ). The by‐products have been used to increase fibre in spreadable cheese flour, pasta and fermented products (Bekhit et al ., ; Alvarez‐Jubete et al ., ; Oliviero & Fogliano, ; Lucera et al ., ), while its juice has been incorporated in soup and nutrient‐enriched tea (Campas‐Baypoli et al ., ; Dominguez‐Perles et al ., ).…”

“…The by‐products have been used to increase fibre in spreadable cheese flour, pasta and fermented products (Bekhit et al ., ; Alvarez‐Jubete et al ., ; Oliviero & Fogliano, ; Lucera et al ., ), while its juice has been incorporated in soup and nutrient‐enriched tea (Campas‐Baypoli et al ., ; Dominguez‐Perles et al ., ). Broccoli and its fractions have potential as functional food ingredients and supplements (Krupa‐Kozak et al ., ; Liu et al ., ).…”

Environmental and Genetic Variation in Essential Mineral Nutrients and Nutritional Value Among Brassica Vegetables

“…In addition, Brassica vegetables provide phenolic compounds, carotenoids, vitamins, and minerals (Kopsell & Sams, 2013;Ku & Juvik, 2013;Kim et al, 2017;Frazie et al, 2017). Although there are many studies reporting glucosinolate and carotenoid composition and their variation among various Brassica crops and different tissues (Liu et al, 2018), studies on essential minerals in various Brassica crops are relatively limited. Available reports on Brassica mineral composition are from different growing conditions and analytical methods (Hanson et al, 2011;Kim et al, 2016a;Kopsell & Sams, 2013).…”