Physicochemical characteristics of guava “Paluma” submitted to osmotic dehydration

Abstract

ABSTRACT. The aim of this work was to evaluate the conservation post process osmotic of guava stored temperature at 5 o C. Guava (Psidium guajava L.), red variety "Paluma" minimally processed by mild osmotic dehydration, were packaged in polyethylene terephthalate (PET) and stored temperature at 5ºC. Non-treated guava, packed in PET trays, was used as control. The treatment used was osmotic dehydration in sucrose syrup at 60ºBrix and physicochemical determinations were pH, total soluble solids (TSS), total titratable acidity (TTA), reducing sugars (RS), total sugars (TS) and parameters related to colour read (a*), chroma (c*), yellow (b*), luminosity (L*) of the fresh and osmotically dehydrated guava slices. The dehydrated fruits lost about 34.45% of water, concentrating contents of soluble solids, total and reducing sugars, when compared to control samples. The pH value remained around 3.76 for the OD fruits and 3.87 for the fresh fruits. The colour of the dehydrated fruits was more intense than the control samples'. The guava slices osmotic dehydration had 21 days of shelf life, showed physicochemical characteristics significantly superior to the control samples', having a stable and high quality product as a result.Keywords: conservation, osmotic treatment, physicochemical parameters.Caracteristicas fisico-quimicas de goiaba "Paluma" submetida à desidratação osmótica RESUMO. O objetivo deste trabalho foi avaliar a conservação pós-processamento osmótico da goiaba "Paluma" armazenada à temperatura de 5 o C. Goiaba (Psidium guajava L.), variedade vermelha "Paluma" minimamente processada submetida à desidratação osmótica branda, foi acondicionada em embalagens de polietileno tereftalato (PET) e armazenada em temperatura de 5 o C. Foi utilizada goiaba não tratada acondicionada em bandejas PET, como controle. O tratamento usado foi a desidratação osmótica em xarope de sacarose a 60 o Brix e as determinações físico-químicas foram pH, sólidos solúveis totais (SST), acidez total titulável (ATT), açúcares redutores (AR), açúcares totais (AT) e parâmetros relacionados com a cor vermelho (a*), croma (c*), amarelo (b*) e luminosidade (L*) das frutas frescas e osmoticamente desidratadas. Os frutos desidratados perderam 34,45% de água, concentrando o conteúdo de sólidos solúveis, açúcares totais e redutores, em relação às amostras controle. O pH permaneceu em torno de 3,76 para os frutos osmoticamente desidratados e 3,87 para os frutos frescos. A cor dos frutos desidratados foi mais intensa que as amostras controle. As fatias de goiabas osmoticamente desidratadas tiveram uma vida de prateleira de 21 dias, apresentando características físico-químicas superiores às amostras controle, as quais foram armazenadas nas mesmas condições e tiveram uma vida de prateleira de 21 dias. Isto proporcionou um produto estável e de elevada qualidade.Palavras-chave: conservação, tratamento osmótico, parâmetros físico-químicos.

Fruit production and quality of guava as a function of biofertilizer and nitrogen fertigation in semiarid

“…Increasing biofertilizer doses also increased the supply of nutrients related to organic acids metabolism, especially potassium, because the biofertilizer used in the experiment present high K content ( Table 2) and, according to (Busato et al, 2011) larger K amounts stimulates TA reduction due to acids degradation, especially malic acid by fruits transpiration. Independently of biofertilizer dose, all TA values recorded in the resent study are higher than those reported by Lima et al (2008), lower than Oliveira et al (2014) results, both of them in study about guava, but all of them are higher than minimum value required by Brazilian government, which is 0.4% (MAPA, 2000). Accordingly Chitarra and Chitarra (2005) detach that less acid fruits are more recommended to consumption as fresh fruit, while more acid fruits are required for food industry.…”

Desenvolvimento e avaliação sensorial de goiaba-passa desidratada osmoticamente

“…Estudos referentes à elaboração de passas de goiaba foram realizados (CORRÊA et al, 2010;PESSOA et al, 2011;OLIVEIRA et al, 2014), porém a transferência de massa foi limitada a uma única temperatura de processo. Estudos relacionados à desidratação osmótica de frutas destacam a influência da temperatura na transferência de massa (CAMPOS et al, 2012;FERRARI et al, 2005).…”

Physical and chemical changes in guava raisin (Psidum guajava l.) produced by osmotic dehydration and drying convective

“…The combination of various drying methods for fruit drying has been applied after the use of pre-treatments, whose purpose is to reduce energy consumption during the removal of water along the process; or else for modifying the structure of the fruit tissue to accelerate the drying process (Zou et al, 2013;Alam et al, 2014;Oliveira et al, 2014).…”