Alessandro Nogueira

Optimisation of the extraction of phenolic compounds from apples using response surface methodology.

The extraction of phenolic compounds from apples was optimised using response surface methodology (RSM). A Box-Behnken design was conducted to analyse the effects of solvent concentration (methanol or acetone), temperature and time on the extraction of total phenolic content, total flavonoids and antioxidant capacity (FRAP and DPPH). Analysis of the individual phenolics was performed by HPLC in optimal extraction conditions. The optimisation suggested that extraction with 84.5% methanol for 15 min, at 28 °C and extraction with 65% acetone for 20 min, at 10 °C were the best solutions for this combination of variables. RSM was shown to be an adequate approach for modelling the extraction of phenolic compounds from apples. Most of the experiments with acetone solutions extracted more bioactive compounds, and hence they had more antioxidant capacity, however, chlorogenic acid and phloridzin had higher yields (32.4% and 48.4%, respectively) in extraction with methanol.

Classification of juices and fermented beverages made from unripe, ripe and senescent apples based on the aromatic profile using chemometrics

The aim of this study was to assess differences between apple juices and fermented apple beverages elaborated with fruits from different varieties and at different ripening stages in the aroma profile by using chemometrics. Ripening influenced the aroma composition of the apple juice and fermented apple. For all varieties, senescent fruits provided more aromatic fermented apple beverages. However, no significant difference was noticed in samples made of senescent or ripe fruits of the Lisgala variety. Regarding the juices, ripe Gala apple had the highest total aroma concentration. Ethanal was the major compound identified in all the samples, with values between 11.83mg/L (unripe Lisgala juice) and 81.05mg/L (ripe Gala juice). 3-Methyl-1-butanol was the major compound identified in the fermented juices. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied and classified the juices and fermented juices based on physicochemical and aroma profile, demonstrating their applicability as tools to monitor the quality of apple-based products.

The Association between Chromaticity, Phenolics, Carotenoids, and In Vitro Antioxidant Activity of Frozen Fruit Pulp in Brazil: An Application of Chemometrics

A total of 19 Brazilian frozen pulps from the following fruits: açai (Euterpe oleracea), blackberry (Rubus sp.), cajá (Spondias mombin), cashew (Anacardium occidentale), cocoa (Theobroma cacao), coconut (Cocos nucifera), grape (Vitis sp.), graviola (Annona muricata), guava (Psidium guajava), papaya (Carica papaya), peach (Prunus persica), pineapple (Ananas comosus), pineapple and mint (A. comosus and Mentha spicata), red fruits (Rubus sp. and Fragaria sp.), seriguela (Spondias purpurea), strawberry (Fragaria sp.), tamarind (Tamarindus indica), umbu (Spondias tuberosa), and yellow passion fruit (Passiflora edulis) were analyzed in terms of chromaticity, phenolic compounds, carotenoids, and in vitro antioxidant activity using ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Data were processed using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Antioxidant capacity was measured by DPPH and FRAP assays, which showed significant (P < 0.01) correlation with total phenolic compounds (r = 0.88 and 0.70, respectively), total flavonoids (r = 0.63 and 0.81, respectively), and total monomeric anthocyanins (r = 0.59 and 0.73, respectively). PCA explained 74.82% of total variance of data, and the separation into 3 groups in a scatter plot was verified. Three clusters also suggested by HCA, corroborated with PCA, in which cluster 3 was formed by strawberry, red fruits, blackberry, açaí, and grape pulps. This cluster showed the highest contents of total phenolic compounds, total flavonoids, and antioxidant activity.

Apple wine processing with different nitrogen contents

The aim of this work was to evaluate the nitrogen content in different varieties of apple musts and to study the effect of different nitrogen concentrations in apple wine fermentation. The average total nitrogen content in 51 different apples juices was 155.81 mg/L, with 86.28 % of the values above 100 mg/L. The apple must with 59.0, 122.0 and 163.0 mg/L of total nitrogen content showed the maximum population of 2.05x 107; 4.42 x 107 and 8.66 x 107 cell/mL, respectively. Therefore, the maximum fermentation rates were dependent on the initial nitrogen level, corresponding to 1.4, 5.1 and 9.2 g/L.day, respectively. The nitrogen content in the apple musts was an important factor of growth and fermentation velocity.

Análise da aptidão industrial de seis cultivares de maçãs, considerando suas avaliações físico-químicas (Dados da Safra 2001/2002)

A agroindustria da maca no Brasil utiliza como materia-prima frutas de descarte provenientes dos processos de selecao para o mercado de frutas in natura. Esse descarte pode representar 30% da producao total. Essas frutas sao processadas a medida que sao encaminhadas para a industria. Em paises europeus, entretanto, tanto para a obtencao de sucos quanto para sidras, sao utilizadas frutas de cultivares selecionadas para tal fim, sendo usados como marcadores de qualidade industrial os teores de acidez, taninos e acucares. Esses componentes sao importantes para a qualidade do produto e envolvem os criterios de cor, sabor e aromas, atributos envolvidos no processo de compra e no habito dos consumidores. Neste trabalho, foram avaliadas seis cultivares de macas (Gala, Eva, Rainha, Fred Hough, Imperatriz e Sansa) em relacao aos parâmetros: teores de solidos soluveis totais, acucares totais e redutores, sacarose, glucose, frutose e compostos fenolicos totais, alem da acidez total titulavel. Foram determinadas as razoes entre acucares totais/acidez total, grau brix/acidez total e a proporcao entre glucose, sacarose e frutose. Pelos resultados, verificou-se que a cultivar Imperatriz apresentou a maior porcentagem de frutose: 66%. O indicador industrial, calculado a partir da razao acucar/acidez, que apresenta como criterio o valor 20, estabelece que essas cultivares podem ser classificadas como de interesse comercial, e nao industrial, uma vez que as seis cultivares apresentaram valores superiores a esse criterio, ou seja, com baixa acidez. As cultivares Sansa, Rainha e Imperatriz apresentaram valores superiores a 200 ppm de compostos fenolicos (valor referencial), o que lhes confere caracteristicas interessantes para serem exploradas pelo setor industrial.

Influence of Fermentation with Hanseniaspora sp. Yeast on the Volatile Profile of Fermented Apple

This study aims to evaluate the aromatic profile of fermented apple, obtained by the action of strains of Hanseniaspora uvarum and Hanseniaspora guilliermondii using two methods of analysis: static headspace and solid phase microextraction (SPME). The results obtained confirm that the strains of the Hanseniaspora genus contributed positively to the aroma profile of fermented apple, producing considerable amounts of esters and higher alcohols. In comparing the methods of analysis of aromatic compounds using headspace and SPME, it was verified that by using the headspace method it was possible to capture amounts that were up to 16 times greater than the value of the volatile compounds obtained by SPME. However, when using SPME, 5 times more compounds were obtained than when using headspace. Even so, in the conditions of this study it was noted that headspace was more efficient in the extraction of the aromatics of fermented apple when taking into consideration the cost effectiveness of both methods.

Effect of alcoholic fermentation in the content of phenolic compounds in cider processing

ABSTRACT The objective of this work was to study the effect of alcoholic fermentation on the content of phenol compounds of five cider apple varieties. The initial content in the apple juice samples, as determined by HPLC, varied from 188.4 to 2776.17 m mg.L -1 . In three of them (DC, PJ, GU), the total phenol compounds remained unaffected by fermentation. However, in two (DM, KE), the final values were lower (55 and 313 mg.L -1 ). In these apple cider, the values of caffeic acid increased from 6.6 mg.L -1 to 41.8 mg.L -1 . The catechin content increased during the process, approximately 13 mg.L -1 independent of the variety. The other phenols class did not present any modifications due to the alcoholic fermentation, maintaining the phenolic compounds of original clarified apple juice in the cider. Keywords : cider, fermentation alcoholic, polyphenols * Author for correspondence INTRODUCTION Polyphenols play important roles in the cider quality as they are related to the color, bitterness and astringency, whose balance defines the overall mouthfeel of the beveradge (Guyot et al., 1998; Alonso-Salces et al., 2001; Lea and Drilleau, 2003; Alonso-Salces, et al., 2004). They may be involved in the fermentative processes, providing the cider aroma, and as inhibitors of the microorganims development, controlling the fermentation rates and avoiding some faults that can develop in cider from the action of lactic acid bacteria such as acidification, mannitol taint, “framboise”, bitterness (Alonso-Salces et al., 2004). Furthermore, the phenolic compounds participate in the formation of sediments during the cider storage, due to their colloidal interaction with the proteins through the van der Waals forces (Siebert et al., 1996; Kawamoto and Nakatsubo, 1997). They can also inhibit the pre-fermentative clarification enzymes (Cowan, 1999). The polyphenols are receiving increasing attention due to their natural antioxidation and health protective properties (Vanzani et al., 2005; Tsao et al., 2005). The polyphenolic composition of a cider depends on the mixture of the apple varieties and the cidermaking procedures. The five main polyphenol classes in the apples are as follows: [1] flavan-3-ols, which includes the monomeric

Avaliação do método de liquefação enzimática na extração de suco de maçã

SUMMARY EVALUATION OF APPLE JUICE EXTRACTION BY THE ENZYME LIQUEFACTION METHOD. The clean technology concept aims to optimize juice extraction in order to obtain high yields, low losses and to manage the use of residues. The preparation of enzymes available nowadays containing depolimerizing activities like pectinases and celulases reach high yields of modified apple juice with less by-products. The main objective of this work was to establish the conditions for apple juice processing by enzymatic liquefaction and to evaluate the apple juice and residual pomace comparing them with that obtained by the traditional pressing extraction. The best conditions found include enzyme concentration of 0.1 mL.Kg -1 and 75 min of reaction at 50 °C. The yield of juice was 83.5% with around 16.5% of residual pomace, which represents 19% more when compared with the results found with traditional pressing processing. When obtained by enzyme liquefaction the juice was more acidic, with higher contents of minerals and of nitrogen than the pressed juice. In the apple pomace left by enzyme liquefaction, the values of acidity and ash of lipids and nitrogen compound were higher than in the pressed pomace but there are significant differences in food fibers although the pectin levels were significantly higher. No differences were found in the proportions of neutral sugars related to cellular walls. Enzyme liquefaction processing shows better results in the juice yield and residual pomace with an advantage of 18.5% over the pressing extraction.

Características de qualidade de cultivares de maçã: avaliação físico-química e sensorial de quinze cultivares

The article shows some figures concerning industrial aplications of samples from apple cultivars. Sensorial evaluation of the apples in natura indicated Melrose, Fred Housh, M 51/90 and Malus 71/90 as able to satisfy the consumer. Sensorial evaluation of the apple juice shows only one interesting variety, Belgolden. The juices showed 12 to 16oBRX and a mean value of malic acid of 0,362g/100mL. Total phenol compounds showed a mean of 316mg/l (C.V.= 22%). Ratios concerning total sugar or total soluble solids: malic acid were too high as compared with the value 20/25 necessary to industrial process. The apple samples were all characterized as bitter, with a set of bitter sweet (Fred Housh, Marquesa, Sansa, Romu, M 51/90 and all Malus) and another of bitter sharp (the others). The most interesting samples for industrial utilization are Belgolden, Coop 25 and 26, Melrose and Malus 67/90). The variety Sansa shows the highest level of fructose and it is an interesting raw material for functional drinks.

Modelling the extraction of phenolic compounds and in vitro antioxidant activity of mixtures of green, white and black teas (Camellia sinensis L. Kuntze)

AbstractThe aim of this study was to model the extraction of phenolic compounds and antioxidant activity from mixtures of green, white and black teas (Camellia sinensis) using a simplex-centroid design coupled with multiple regression analysis. White tea showed the highest content of phenolic compounds and in vitro antioxidant activity, while black tea presented the opposite behaviour. The lowest values found in black tea are due to the oxidation of phenolic antioxidants during the fermentation. Gallic acid, chlorogenic acid, epicatechin, epigallocatechin gallate, epigallocatechin, and epicatechin gallate showed a significant correlation (P < 0.05) between all the antioxidant assays. All the mathematical models proposed were significant (P < 0.05) and showed high determination coefficients (R2adj > 0.80). A simultaneous optimization was performed using the desirability function and the optimum condition to maximize the extraction of epicatechin, epigallocatechin gallate, epicatechin gallate, as well as the antioxidant activity (DPPH and FRAP). The results showed that pure white tea was the best solution for obtaining a higher content of antioxidants. Graphical abstractExtraction process of phenolic compounds using response surface methodology