Abstract Guava (Psidium guajava L.) is fruit with very short shelf life due to associated with the loss of firmness in the pulp and information on the activity of enzymes that degrade pectic substances, as well as the amount of pectin, is very contradictory and not clearly defined. This work showed that the firmness of the fruit decreased sharply on the first four days of ripening. The identified phenolic compounds had their content increased with fruit maturation. The addition of the enzymes cellulase and hemicellulase in the pectin extraction in fruits of Psidium guajava revealed higher contents of this polyssacaride that the ones reported in literature, highlighting pectin as the responsible for the firmness of these fruits at more adequate contents. β-D-glucosidase was identified as one of the responsible enzymes for the maturation of P. guajava fruits. Thus, studies about possible inhibitory effects of this enzyme in P. guajava fruits may reveal an important tool to reduce pectin release and early maturation of these fruits.

Resumo A goiaba é uma fruta altamente perecível, devido ao seu intenso metabolismo durante o amadurecimento, com vida útil que pode chegar a cinco dias em temperatura ambiente. A perda de firmeza durante o amadurecimento é devida à atividade das enzimas hidrolíticas, que promovem a solubilização dos constituintes da pectina da parede celular. Embora a goiaba seja considerada rica em pectina, as quantidades relatadas na literatura não excedem 2,4% e tal conteúdo não explica a sua responsabilidade pela firmeza dos frutos. O objetivo deste estudo foi extrair pectina da polpa de goiaba durante sete dias de amadurecimento, por dois métodos (extração de etanol e EDTA). Sugerem-se modificações nos métodos, adicionando aos resíduos de extração, celulase e pectinase para degradar a estrutura da parede celular do fruto e obter maiores quantidades de pectina e, portanto, implicar sua participação na manutenção da firmeza dos frutos. Foi possível inferir que não há diferenças nos níveis de pectina extraídos pelos dois métodos, devido à contaminação do açúcar. A partir da nova etapa de execução nos métodos, a extração foi mais eficiente: 9,10% de pectina com EDTA e 7,63% com etanol. Os conteúdos de pectina encontrados foram superiores aos mencionados na literatura, explicando melhor sua responsabilidade na firmeza dos frutos.

Abstract Guava is a highly perishable fruit due to its intense metabolism during ripening, with a shelf life of up to five days at room temperature. The loss of firmness during ripening is caused by the activity of hydrolytic enzymes that promote dissolution of the pectin constituents of the cell wall. Although guava is considered to be rich in pectin, the amounts reported in the literature do not exceed 2.4%, a content indicating it is not responsible for the firmness of guava. The aim of this study was to extract pectin from the guava pulp during 7 days of ripening by two methods (ethanol and EDTA extraction) and suggest modifications in the methods by adding to the extraction residue, cellulase and pectinase to degrade the cell wall structure of the fruit and obtain larger amounts of pectin, which would imply the participation of pectin in the maintenance of fruit firmness. It was possible to infer there were no differences in the pectin levels extracted by the two methods, due to sugar contamination. As from the new stage in the execution by the two methods, the extraction was more efficient: 9.10% of pectin with EDTA and 7.63% with ethanol. The pectin contents found were higher than those mentioned in the literature, better explaining their responsibility in fruit firmness.

Resumo Neste estudo, caracterizaram-se os compostos fenólicos e avaliou-se a atividade antibacteriana de extratos obtidos da farinha da casca de jabuticaba (FCJ). Os compostos fenólicos da FCJ foram extraídos de quatro formas: a) extrato acetônico - 1 g FCJ: 10 mL acetona 70%, duas horas em repouso; b) extrato aquoso - 1 g FCJ: 15 mL água, sob agitação; c) extrato etanólico - 1 g FCJ: 15 mL etanol acidificado, sob agitação; e d) extrato metanólico - 1 g FCJ: 50 mL metanol 50%, sob refluxo. A atividade antibacteriana foi avaliada pela técnica de difusão cavidade em Ágar, utilizando-se os microrganismos Escherichia coli ATCC 11229, Salmonella cholerasuis ATCC 6539, Pseudomonas aeruginosa ATCC 15442, Staphylococcus aureus ATCC 6538 e Listeria monocytogenes ATCC 19117. Os extratos etanólico e metanólico apresentaram os teores mais elevados de compostos fenólicos, sobretudo o cloreto de cianidina, catequina e epicatequina. Os extratos não inibiram o crescimento de Escherichia coli e Salmonella choleraesuis, mas inibiu em 30% o crescimento de Pseudomonas aeruginosa na concentração do extrato de 250 µg mL-1. A maior inibição de crescimento registrada foi de 41,8% pelo extrato etanólico, seguida pela inibição de 36% pelo extrato metanólico, contra as bactérias Staphylococcus aureus e Listeria monocytogenes, revelando assim a potencialidade destes extratos como possível alternativa para utilização na indústria de alimentos e/ou farmacêutica.

Abstract The phenolic compounds from various extracts of jabuticaba skin powder (JSP) were characterized in this study, and the antibacterial activity assessed. The phenolic compounds were extracted from the JSP using four methods: a) acetone extraction - 1 g JSP: 10 mL 70% acetone, resting for 2 hours; b) aqueous extract - 1 g JSP: 15 mL water, under agitation; c) ethanolic extract - 1 g JSP: 15 mL acidified ethanol, under agitation; and d) methanolic extract - 1 g JSP: 50 mL 50% methanol, under reflux. The antibacterial activity was evaluated by the agar diffusion assay, using Escherichia coli ATCC 11229, Salmonella choleraesuis ATCC 6539, Pseudomonas aeruginosa ATCC 15442, Staphylococcus aureus ATCC 6538 and Listeria monocytogenes ATCC 19117. The ethanolic and methanolic extracts showed the highest levels of phenolic compounds, especially of cyanidin chloride, catechin and epicatechin. The extracts did not inhibit the growth of Escherichia coli and Salmonella choleraesuis, but inhibited 30% of the growth of Pseudomonas aeruginosa with an extract concentration of 250 µg mL-1. Against Staphylococcus aureus and Listeria monocytogenes the highest inhibitory effect observed was 41.8% for the ethanolic extract, followed by 36% inhibition by the methanolic extract, thus revealing the potential of these extracts as possible alternatives for use in the food and/or pharmaceutical industries.

Resumo A goiaba é uma fruta altamente perecível devido ao seu rápido metabolismo durante a maturação. A fruta sofre perda de firmeza alguns dias após a colheita, o que impede seu armazenamento por longos períodos. Assim, há um grande interesse no desenvolvimento de novos tipos de embalagens que prolonguem sua vida útil, propiciando características sensoriais e nutricionais desejáveis. Este estudo investigou o amolecimento das goiabas cv. Pedro Sato tratadas com filmes de quitosana de diferentes pesos moleculares (132, 228 e 245 kDa), em concentrações de 0,5% e 1,5%. Assim, a perda de massa, a firmeza, o conteúdo de pectinas e as atividades das enzimas hidrolíticas pectina metilesterase e β-D-glucosidase foram avaliados durante oito dias de armazenamento, à temperatura ambiente. Os resultados mostraram que as goiabas tratadas com quitosana 245 kDa, na concentração de 1,5%, apresentaram menor perda de peso e teor de pectina solúvel, bem como maior firmeza e conteúdo da pectina total, em comparação com os outros tratamentos. O tratamento com quitosana 245k Da, na concentração de 0,5%, resultou em atividades menores das enzimas hidrolíticas analisadas. Os tratamentos com quitosana em diferentes concentrações foram eficazes na manutenção da qualidade pós-colheita de goiabas quando comparados com o controle, estendendo sua vida útil por oito dias.

Abstract Guava is a highly perishable fruit due to its rapid metabolism during maturation, suffering a loss of firmness a few days after harvesting, which prevents its storage for long periods. Thus there is great interest in the development of new types of packaging that extend its useful life, providing desirable sensory and nutritional characteristics. This study investigated the softening of “Pedro Sato” guavas subjected to treatment with chitosan films of different molecular weights (132, 228 and 245 kDa), at concentrations of 0.5% and 1.5%. Thus the loss of mass, firmness, pectin content and activities of the hydrolytic enzymes pectin methylesterase and β-D-glucosidase were evaluated for eight days of storage at room temperature. The results showed that the product treated with chitosan 245kDa at a concentration of 1.5% showed lower weight loss and loss of soluble pectin content, as well as greater firmness and total pectin content, as compared to the other treatments. The treatment with chitosan 245 kDa at a concentration of 0.5% resulted in lower activities of the hydrolytic enzymes analyzed. When compared with the control, the treatments with chitosan at different concentrations were effective in maintaining the postharvest quality of guavas, extending their life by eight days.

Abstract Jabuticaba skin flour (JSF), rich in antioxidants and fibre, was used in order to develop four restructured hams in different combinations with meat: 0% control – without the addition of JSF, with the addition of 0.5% JSF, 1.0% JSF and 1.5% JSF, meeting, therefore, the growing demand for meat products with functional appeal. Physicochemical characterizations and sensory analysis were performed, evaluating the impact of information on possible health benefits and the effect on storage. Restructured hams with JSF had higher contents of phenolic compounds; greater weight loss; a darker shade; texture profile with smaller parameters of stiffness, cohesiveness, adhesiveness, flexibility and chewiness (except the restructured ham with 0.5% JSF). Phenolic compounds, pH values, colour and TBARs did not differ with storage time, but were statistically different among JSF concentrations. Panellists preferred the restructured ham without JSF, however, the analysis of variance for overall aspect did not show a significant difference between the restructured ham “control” and those added with 0.5% and 1.0% JSF, after informing the panellists that they would possibly bring health benefits. It is concluded that it is possible to prepare and store restructured hams with JSF, at concentrations of 0.5% and 1.0% with good acceptance.

RESUMO O Cerrado é o maior bioma no Estado de Minas Gerais-Brasil, representado uma biodiversidade de espécies frutíferas, destacando a cagaiteira (Eugenia dysenterica). Frutos de cagaiteira são considerados uma opção importante para fruticultura, por apresentarem fonte de compostos fenólicos com propriedades antioxidantes e teores de minerais que podem contribuir com efeitos benéficos à saúde. Neste estudo, caracterizaram-se os compostos fenólicos por cromatografia líquida de alta eficiência e avaliaram-se os teores de minerais presentes em frutos de cagaiteira em estádio de maturação maduros e verdes. Em relação aos minerais, frutos maduros e verdes destacam-se por serem ricos em potássio. Os frutos verdes são ricos em boro, enquanto os frutos maduros são fonte desse mineral. Nos frutos de cagaiteira maduros e verdes, foram identificados os compostos fenólicos: os ácidos gálico, cafeico, vanílico, p-cumárico, siríngico, ferúlico e salicílico, epicatequina, quercetina e rutina, sendo os maiores teores dos compostos os ácidos cafeico, p-cumárico, siríngico e ferúlico, epicatequina e rutina identificados nos frutos verdes, enquanto para frutos maduros o destaque foi para os ácidos gálico, vanílico esalicílico e quercetina. Assim, frutos de cagaita podem apresentar grande potencial para aplicações alimentares, terapêuticas e medicinais, trazendo benefícios à saúde.

ABSTRACT Cerrado is the largest biome in the state of Minas Gerais-Brazil, represented by a biodiversity of fruit species, especially cagaita (Eugenia dysenterica). Cagaita fruits are considered an important option for fruit growing, because they are source of phenolic compounds with antioxidant properties and mineral content that can contribute with beneficial health effects. In this study, phenolic compounds were characterized by high-performance liquid chromatography and the mineral content of ripe and unripe cagaita fruits was evaluated. Regarding minerals, ripe and unripe fruits stand out due to their high potassium content. Unripe fruits are rich in boron while ripe fruits are source of this mineral. ripe and unripe cagaita fruits have the following phenolic compounds: gallic, caffeic, vanillic, p-coumaric, siringeic, ferulic and salicylic acids, epicatechin, quercetin and rutin, the highest contents of these compounds are caffeic, p-coumaric, siringeic and ferrulic, epicatechin and rutin identified in unripe fruits, while ripe fruits have high contents of gallic, vanillic and quercetin acids. Thus, cagaita fruits have great potential for food, therapeutic and medicinal applications bringing health benefits.

Resumo Folhas de mandioca (Manihot esculenta Crantz) são resíduos agroindustriais que apresentam potencial para o consumo humano, sendo fontes de proteínas, vitaminas, minerais e de substâncias antioxidantes, com destaque para os compostos fenólicos. No presente estudo, o objetivo foi identificar e quantificar os compostos fenólicos presentes em diferentes extratos da farinha de folhas de mandioca (FFM), cultivar Pão da China, e avaliar seu potencial antioxidante. A extração dos compostos fenólicos foi realizada utilizando três métodos de extração: a) refluxo com metanol/água (50:50, v/v); b) maceração com etanol/água (50:50, v/v) seguido de refluxo com acetona/água (70:30, v/v); c) maceração com metanol PA. A caracterização e quantificação foi realizada por cromatografia líquida de alta eficiência e a atividade antioxidante, determinada pelos métodos ABTS e β-caroteno/ácido linoleico. Foram encontrados cinco compostos fenólicos nos extratos da FFM: ácido gálico, galocatequina, catequina, ácido clorogênico e epigalocatequina, sendo a extração com metanol/água (50:50, v/v) a que revelou a presença do maior número destes compostos e o maior potencial antioxidante. Entre os fenólicos da FFM, independentemente do extrato, a catequina foi o majoritário. Pode-se inferir que a atividade antioxidante dos extratos da FFM está relacionada com a presença de compostos, pois a extração com maior teor desses compostos foi a que demonstrou maior potencial antioxidante.

Summary Cassava (Manihot esculenta Crantz) leaves are agroindustrial residues with the potential for human consumption, being sources of protein, vitamins, minerals and antioxidant substances, especially phenolic compounds. The objective of the present study was to identify and quantify the phenolic compounds present in different cassava leaf flour (FFM) extracts, from the Pão da China cultivar, and evaluate their antioxidant potential. The phenolic compounds were extracted using the following three methods: a) refluxing with methanol/water (50:50, v/v); b) maceration with ethanol/water (50:50, v/v) followed by refluxing with acetone/water (70:30, v/v); c) maceration with methanol PA. The compounds were identified and quantified by high performance liquid chromatography, and the antioxidant activity determined by the ABTS and β-carotene/linoleic acid methods. Five phenolic compounds were found in the FFM extracts: gallic acid, gallocatechin, catechin, chlorogenic acid and epigallocatechin, extraction with methanol/water (50:50, v/v) revealing the presence of the greatest number of these compounds and the highest antioxidant potential. Of the phenolic compounds found in FFM, catechin was the major one, independent of the extraction method. It can be inferred that the antioxidant activity of the FFM extracts is related to the presence of phenolic compounds, since the sample with the highest content of these compounds demonstrated the highest antioxidant potential.

Pumpkin (Cucurbita maxima), popularly known as squash, is a widely grown vegetable in Brazil. In this study, pumpkin seed flours (PSF) with different granulometries were used: PSF 1 (medium granulometry) and PSF 2 (coarse granulometry) in the preparation of cereal bars (CB) with different combinations with brown oats. Five formulations were prepared: CB-1 (control - 25% brown oats and 0% PSF); CB-2 (12.5% PSF 1 and 12.5% brown oats); CB-3 (25% PSF 1 and 0% brown oats); CB-4 (12.5% PSF 2 and 12.5% brown oats); and CB-5 (25% PSF 2 and 0% brown oats). The acceptance test results were analyzed in a conventional preference mapping which indicated that the bars CB-2 and CB-5 received mostly the maximum hedonistic score. With the objective of developing a cereal bar replacing oats with PSF, the bars CB-2 and CB-5 were compared to the conventional bar CB-1. The cereal bars CB-2 and CB-5 showed an increase in crude protein (87.5% and 62.5%) and in dietary fiber (77% and 44%), respectively. These results allowed the classification of CB-2 and CB-5 as fiber sources; they can, therefore, be classified as light products according to the Brazilian legislation.

Acerola is a fruit that can be consumed in the form of juice and pulp. However, during its processing, a large amount of waste is generated (seed and bagasse). Adding value to these by-products is of great interest, since their use can enrich foods with nutrients and fiber. In this study, we performed phytochemical screening, determined the proximate and mineral composition, bioactive compounds and the technological functional properties of acerola seed flour and acerola bagasse flour. Seeds were dried in a ventilated oven at ± 45 °C and the bagasse was lyophilized. Samples were ground, stored in flasks protected from light. Phytochemical screening revealed metabolites of nutritional and pharmacological interest and no potentially toxic substances in the flours. Seed flour and bagasse flour showed high levels (g 100 g- 1 of dry matter - DM) of soluble fiber: 4.76 and 8.74; insoluble fiber: 75.76 and 28.58, and phenolic compounds: 4.73 and 10.82, respectively. The flours also showed high absorption of water, oil and emulsion stability, presenting potential for inclusion in meat products and bakery products.