Abstract Oral candidiasis is a common fungal infection that affects the oral mucosa, and happens when Candida albicans interacts with bacteria in the oral microbiota, such as Streptococcus mutans, causing severe early childhood caries. C. albicans and S. mutans mixed biofilms are challenging to treat with conventional antimicrobial therapies, thus, new anti-infective drugs are required. Objective This study aimed to test a drug delivery system based on chitosan microparticles loaded with geranium and lemongrass essential oils to inhibit C. albicans and S. mutans mixed biofilms. Methodology Chitosan microparticles loaded with essential oils (CM-EOs) were obtained by spray-drying. Susceptibility of planktonic were performed according CLSI at 4 to 2,048 µg/mL. Mixed biofilms were incubated at 37ºC for 48 h and exposed to CM-EOs at 256 to 4,096 µg/mL. The antimicrobial effect was evaluated using the MTT assay, with biofilm architectural changes analyzed by scanning electron microscopy. RAW 264.7 cell was used to evaluate compound cytotoxicity. Results CM-EOs had better planktonic activity against C. albicans than S. mutans. All samples reduced the metabolic activity of mixed C. albicans and S. mutans biofilms, with encapsulated oils showing better activity than raw chitosan or oils. The microparticles reduced the biofilm on the slides. The essential oils showed cytotoxic effects against RAW 264.7 cells, but encapsulation into chitosan microparticles decreased their toxicity. Conclusion This study demonstrates that chitosan loaded with essential oils may provide an alternative method for treating diseases caused by C. albicans and S. mutans mixed biofilm, such as dental caries.

Resumo Este trabalho teve como objetivo comparar as características físico-químicas e a aceitabilidade de um doce tipo paçoca, elaborado a partir de torta de amêndoa de castanha-de-caju com dois produtos similares comerciais de amendoim. A paçoca foi preparada com 59,5% de torta, 25,0% de açúcar, 0,5% de sal, 5,0% de farinha de mandioca e 10,0% de óleo de milho, sendo moídos juntos e moldados em forma de paralelepípedo. Os produtos foram analisados para determinação de características físico-químicas (umidade, cinzas, lipídeos, proteínas, carboidratos, atividade de água), cor instrumental (L*a*b*) e aceitação sensorial (escala hedônica de 9 pontos). Os resultados foram comparados por ANOVA e Teste de Tukey (α=0,05). Pequenas diferenças físico-químicas foram observadas: a umidade variou de 1,01 a 2,79%; cinzas, de 1,23 a 2,75%; lipídeos, de 30,28 a 31,27%; proteínas, de 14,19 a 16,90%; carboidratos, de 50,21 a 54,07%, e atividade de água, de 0,295 a 0,429. Apesar de a paçoca de amêndoa de castanha-de-caju ser mais clara e menos vermelha (L*=74,48, a*=1,38) que as comerciais de amendoim (valores médios L*=54,33, a*=8,08), apresentou aceitação semelhante à desses produtos, que variaram entre 7,0 e 7,8 (“gostei” a “gostei muito” da escala hedônica). Considerando-se a atividade de água inferior a 0,6, a paçoca de torta de amêndoa de castanha-de-caju pode ser considerada microbiologicamente estável à temperatura ambiente, sendo uma boa alternativa para a utilização do subproduto da extração do óleo de amêndoas quebradas.

Summary This work aimed to compare the physicochemical characteristics and acceptance of a cashew nut meal candy with two similar commercial products made from peanut. The candy was prepared using 59.5% cashew nut meal, 25.0% sugar, 0.5% salt, 5.0% cassava flour and 10.0% corn oil ground together and moulded into a parallelepiped shape. The products were analysed for their physicochemical characteristics (moisture, ash, lipids, proteins, carbohydrates, water activity), instrumental colour (L*a*b*) and sensory acceptance (9 point hedonic scale). The results were compared by ANOVA and the Tukey’s test (α=0.05). Slight physicochemical differences were observed: the moisture content ranged from 1.01 to 2.79%, ash from 1.23 to 2.75%, lipids from 30.28 to 31.27%, proteins from 14.19 to 16.90%, carbohydrates from 50.21 to 54.07% and water activity from 0.295 to 0.429. Although the cashew nut candy was lighter and less red (L* = 74.48, a* = 1.38) than the commercial peanut candy (mean values L* = 54.33, a* = 8.08), it presented similar acceptance to those products, the scores varying between 7.0 and 7.8 (“liked” to “liked very much” on the hedonic scale). Considering that its water activity was lower than 0.6, the cashew nut candy could be considered microbiological stable at room temperature and could be regarded as a good alternative for the use of the residue obtained after the extraction of oil from broken kernels.