Effect of food additives on the antioxidant properties and microbiological quality of red guava juice

Abstract

Guava is a tropical fruit that has a high potential for agroindustrial use, also known antioxidant property mainly attributed to vitamin C and carotenoids content. The objective of this study was to evaluate the influence of food preservatives, individually or combined, on the antioxidant properties of red guava nectar during storage. Nectars added of different additives were stored in the dark for 180 days and evaluated at the processing day and every 90 days for physico-chemical parameters, color, bioactive compounds content, total antioxidant activity (TAA), the microbiologica and sensory quality. Was not observed changes in quality parameters (P>0.05), since the guava nectars were presented in accordance with Standards of Identity and Quality required by Brazilian law. According to data for antioxidante compounds and total antioxidant activity (TAA), can conclude that nectars added sodium metabisulfite and sodium metabisulfite + sodium benzoate showed, after 90 days of storage, a lower reduction in total extractable polyphenols (TEP) and vitamin C content, being the TEP reduction directly correlated with TAA.

Effect of industrial processing for obtaining guava paste on the antioxidant compounds of guava (Psidium guajava l.) ‘Paluma’ cv.

“…In the process of obtaining guava pulp, there is water loss, with concentration of compounds. Subsequently, the process of obtaining guava paste uses more severe temperatures, with loss / degradation of ascorbic acid, which corroborates results found in literature (JAWAHEER et al, 2003;TEIXEIRA et al, 2006;FREIRE et al, 2013;ORDÓÑEZ-SANTOS et al, 2013;SILVA et al, 2016), where more severe heat treatment of by-products causes degradation of ascorbic acid present in fresh fruit. Evaluating the effect of the thermal process, Jawaheer et al (2003) found that guava processing resulted in the retention of 37.5% ascorbic acid in jelly and 79.6% in juice, since the production of jelly involves a more severe heat treatment than that of juice.…”

“…Ascorbic acid is very sensitive and may suffer degradation during the processing and storage of products and by-products containing it (TEIXEIRA et al, 2006;FREIRE et al, 2013;ORDÓÑEZ-SANTOS et al, 2013;SILVA et al al., 2016). According to Freire et al (2013), there was a nearly 70% reduction in ascorbic acid content for frozen guava pulp (-18 o C for 3 months), when compared to the fresh fruit.…”

“…Guava (Psidium guajava L.) is among Brazilian tropical fruits that stand out for its economic and nutritional importance (AMORIM et al, 2015;ARAÚJO et al, 2015;SEBRAE, 2016), and Brazil is among the world's top three fruit producers (TEIXEIRA et al, 2006;MENEZES et al, 2009). The fruit has been extensively studied and although it is an excellent source of exogenous nutrients and antioxidants, such as vitamin C, carotenoids, phenolic compounds and flavonoids (MELO et al, 2008;SOUSA et al, 2011a;2011b;VIEIRA et al, 2011;FREIRE et al, 2012;ORDÓÑEZ-SANTOS et al, 2014;ARAÚJO et al, 2015;SILVA et al, 2016), the consumption of fresh guava is still low in the country, estimated at 300g / inhabitant / year (SEBRAE, 2016). On the other hand, guava byproducts are quite consumed, and about 70% of guava production aimed at industrial processing is of 'Paluma' cultivar (AMORIM et al, 2015).…”

“…The antioxidant capacity of guava has been gaining prominence (ORDÓÑEZ-SANTOS and VÁZQUEZ-RIASCOS, 2010;FU et al, 2011;2016;SOUSA et al, 2011a;2011b;VIEIRA et al, 2011;ORDÓÑEZ-SANTOS et al, 2014;ARAÚJO et al, 2015;SILVA et al, 2016;ZAHIN et al, 2016). The method of reducing the DPPH radical (1,1-diphenyl-2-picryl-hydrazyl), monitored by decreasing the absorbance at a given wavelength, is one of the most widely used methods for determining the antioxidant capacity of an extract (BRAND-WILLIAMS et al, 1995;AMIN e MUKHRIZAH, 2006;MELO et al, 2008;DUZZIONI et al, 2010;SOUSA et al, 2011a;2011b; VIEIRA et al, 2011; HERNÁNDEZ-ACOSTA et al, 2011; ARAÚJO et al, 2015).…”

“…The identification of the composition of antioxidant substances in foods, as well as the verification of possible changes or degradations that may occur during processing and storage due to the interference of factors such as temperature, light, pH, relative humidity, gas composition and enzymatic system is of utmost importance (RODRIGUEZ-AMAYA, 1999;TEIXEIRA et al, 2006;ORDÓÑEZ-SANTOS and VÁZQUEZ-RIASCOS, 2010;FREIRE et al, 2013;ORDÓÑEZ-SANTOS et al, 2013;SILVA et al, 2016). This work is a comparative study with three observational conditions, defined as the stages of industrial processing (fresh fruit, guava pulp and guava paste), with the objective of evaluating the effect of industrial processing on the production of guava by-products 'Paluma' cv., such as guava pulp and guava paste, on the contents of ascorbic acid, total carotenoids, total phenolics and total flavonoids, as well as on the antioxidant capacity of the fruit and by-products.…”