Flour of banana (Musa AAA) peel as a source of antioxidant phenolic compounds

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Banana peel is an underused by-product that can be processed to obtain flour that is more easily stored for further uses. The extracts of banana peel flour exhibited a high total phenolic content (around 29 mg/g, as GAE) due to the occurrence of important amounts of flavonoid phenolics: highly polymerized prodelphinidins (around 3952 mg/kg), followed by decreasing lower contents of flavonol glycosides (mainly 3-rutinosides and predominantly quercetin-based structures, accounting for around 129 mg/kg), B-type procyanidin dimers and monomeric flavan-3-ols (jointly around 126 mg/kg). The high total phenolic content of extracts of banana peel flour is likely responsible for the very high antioxidant activity (mu M/g, as Trolox equivalents) measured by three different methods: FRAP, around 14 mu M/g; ABTS, around 242 mu M/g; and ORAC, around 436 mu M/g. All these results suggest the interest in going in depth of the good use of banana peel as a profitable source of bioactive phenolic compounds. (C) 2013 Elsevier Ltd. All rights reserved.55397403Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Fondo Social Europeo [POII10-0061-4432]Junta de Comunidades de Castilla-La Mancha [POII10-0061-4432]Spanish Ministerio de Economia y Competitividad [AGL2011-29708-C02-02]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fondo Social Europeo [POII10-0061-4432]Junta de Comunidades de Castilla-La Mancha [POII10-0061-4432]Spanish Ministerio de Economia y Competitividad [AGL2011-29708-C02-02

Phenolic composition of the berry parts of hybrid grape cultivar BRS Violeta (BRS Rubea x IAC 1398-21) using HPLC-DAD-ESI-MS/MS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The grape is considered a major source of phenolic compounds when compared to other fruits and vegetables, however, there are many cultivars with distinct characteristics directly linked to phenolic profile. Thus, the present study aimed to identify and quantify, for the first time and in detail, the phenolic compounds present in the skin, flesh and seeds of BRS Violeta grape berry using combination of SPE methodologies and analytical HPLC-DAD-ESI-MS/MS. The study was extended to the different berry parts and the most important grape and wine phenolic families, and has revealed interesting features. Violeta grape has a very thick skin (46% of grape weight) that accumulated the most of grape phenolic compounds: great amount of anthocyanins (3930 mg/kg, as malvidin 3,5-diglucoside), together with also important amounts of flavonols (150 mg/kg, as quercetin 3-glucoside), hydroxycinnamic acid derivatives (HCAD; 120 mg/kg, as caftaric acid), and proanthocyanidins (670 mg/kg, as (+)-catechin); in contrast, it seems to be a low resveratrol producer. Violeta grape seeds accounted for similar proportions of low molecular weight flavan-3-ols (mainly monomers; 345 mg/kg, as (+)-catechin) and proanthocyanidins (480 mg/kg, as (+)-catechin). Violeta grape is a teinturier cultivar, but it only contained traces of anthocyanins and low amounts of all the other phenolic types in its red-colored flesh. The anthocyanin composition of Violeta grape was dominated by anthocyanidin 3,5-diglucosides (90%). Within flavonols, myricetin-type predominated and kaempferol-type was missing. In addition to expected hydroxycinnamoyl-tartaric acids, several isomeric esters of caffeic and p-coumaric acids with hexoses were tentatively identified, accounting for relevant proportions within the pool of HCAD. Although pending of further confirmation over successive vintages, the aforementioned results suggest that BRS Violeta grape cultivar could be considered an interesting candidate for the elaboration of highly colored and antioxidant-rich grape juices and wines. (C) 2013 Elsevier Ltd. All rights reserved.541354366Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fondo Social EuropeoJunta de Comunidades de Castilla-La Mancha [POII10-0061-4432]Spanish Ministerio de Economia y Competitividad [AGL2011-29708-C02-02]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CNPq [486967/21012-3-CNPq]Junta de Comunidades de Castilla-La Mancha [POII10-0061-4432]Spanish Ministerio de Economia y Competitividad [AGL2011-29708-C02-02