Qualidade de goiaba „paluma‟ minimamente processada sob recobrimentos a base de quitosana, cloreto de cálcio e alginato

• Ano de defesa: 2015
• Autor(a) principal: Melo, Fernanda dos Santos Nunes de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Química e Bioquímica de Alimentos; Programa de Pós-Graduação em Ciência e Tecnologia de Alimentos; UFPB
• Palavras-chave em Português: Antioxidantes; Bioativos; Microbiologia; Sensorial; Antioxidants; Bioactive; Microbiology; Sensory; CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/9452

This study aimed to evaluate the quality and antioxidant activity of guava (Psidium guajava L.) minimally processed cv. Paluma under different biodegradable coatings to basis chitosan, alginate and calcium. The Guavas "Paluma" were derived from a commercial planting in the city of Nova Floresta-PB and the minimum processing was performed according to good practices. The coatings used were: chitosan (2%), sodium alginate (1%) and calcium chloride (1%). The analyzes were: physiological, physical, chemical physical, bioactive compounds, antioxidant activity, microbiology and sensory. The slices of guava who received no coating showed higher concentrations of oxygen and less carbon dioxide. Slices treated with calcium chloride plus chitosan showed greater weight loss at the end of the twelve days. Treatment of calcium chloride expressed best results firmness of the fruit pulp, but showed lower scores for sensory acceptance texture than the other treatments on the sixth day. For color variable a*, slices treated with calcium chloride plus chitosan showed higher values, did not differ from control and calcium chloride coating. Regarding the b* values were higher for the calcium chloride, did not differ from alginate. The a*/b* relation indicated that the slices were in red-orange color throughout storage. Fruit without any coating contained higher soluble solids. The acidity was increased in slices treated with calcium chloride, differing only from alginate coating. The pH was higher in slices treated with chitosan, differing from the control. In the microbiological quality guava slices treated with chitosan showed to be free from fecal contamination and safe amount of microorganisms (coliform 35 ° C, molds and yeasts) until the eighth day of storage. Regarding the sensory analysis, the coating of calcium chloride and alginate maintained acceptable appearance until the sixth day. On the eighth day, only the coatings of chitosan and control achieved acceptable grades for the flavor attribute. For the texture attribute, all coatings had the note in the acceptance limit until the sixth day, except the calcium chloride coating. For global acceptance control obtained acceptable notes until the sixth day of storage. For purchase attitude, just the chitosan coating obtained acceptable notes until the eighth day of storage. The coatings did not affect the content of ascorbic acid, there was a decrease of this bioactive compound during storage. Slices coated with sodium alginate showed the highest lycopene content after 12 days. The coating of chitosan showed the highest levels of β-carotene at the end of storage. There was no difference in the content of polyphenols and antioxidant activity by the ABTS+- method during storage, differing only among the treatments. Slices treated with calcium chloride showed the highest average values of TEP. The antioxidant activity by ABTS+- method in slices coated with calcium chloride and calcium chloride plus chitosan was higher than the control. However, by the DPPH method there was variation in antioxidant activity during the twelve days and among treatments, where AT was lower in slices coated with calcium chloride and calcium chloride plus chitosan when compared with slices of other coatings. The chitosan coating is the most suitable for the conservation of guava 'Paluma' minimally processed in slices, once that kept the product quality characteristics, was acceptable sensory and maintained microbiological quality until the eighth day of storage.