Uso da quimiometria na caracterização óptica de polpas de frutas típicas da microrregião de Salinas-MG para estudo do controle microbiológico utilizando luz ultravioleta / Use of chemiometry in the optical characterization of typical fruit pulps of the Salinas-MG microregion for study of microbiological control using ultraviolet light

Agroindústrias regionais produzem polpas de frutas artesanalmente, sendo o uso de luz ultravioleta (UV) uma alternativa de controle microbiológico. A pesquisa com UV requer a caracterização da polpa, que pode ser simplificada através dos componentes principais. Este trabalho objetivou caracterizar, por meio de análises físico-químicas, polpas de frutas e definir propriedades que correspondem à maior parte da variabilidade amostral. Utilizou-se polpas de cajá manga, coquinho azedo, maracujá do mato, tamarindo e umbu em que dez parâmetros foram avaliados. Submetidos a análise de componentes principais, absorbância em 254 nm e condutividade elétrica representaram 80,21% da variabilidade com separação total das amostras em função da fruta. Essas variáveis foram utilizadas na pesquisa com UV para diferenciação e classificação das amostras.

Effect of dynamic high pressure on emulsifying and encapsulant properties of cashew tree gum.

Dynamic high pressure (DHP) has been applied in the physical modification of biopolymers as polysaccharides, proteins and gums. It is known that DHP is able to promote degradation of polysaccharides (e.g. molecular weight reduction). However, few studies have assessed the effect of DHP on the emulsifying and encapsulating properties of polysaccharides. Thus, this study aimed to investigate the effect of DHP on the emulsifying (average droplet size and particle size distribution, optical and confocal scanning laser microscopy, rheology, zeta potential and electric conductivity, creaming index, and turbidity) and encapsulating (scanning electronic microscopy, flavor retention, average droplet size, and particle size distribution) properties of cashew tree gum (CG). The application of DHP process improved the emulsifying capacity of cashew tree gum (CG) by reducing the medium droplet size (D3,2 and D4,3), increasing the turbidity and improving the emulsion stability. However, no effect of DHP was observed on the encapsulating capacity of CG.

Effect of dynamic high pressure on technological properties of cashew tree gum (Anacardium occidentale L.).

Dynamic high pressure (DHP) appears to be an alternative approach to physical modification of polysaccharides aimed improving their technological properties. Therefore, its effect on the functional properties of polysaccharides (i.e., oil absorption capacity, emulsifier, and rheology) needs to be investigated. Cashew tree gum (CG) is a biological macromolecule that has been proposed to be used as an emulsifier in beverage emulsions. To the best of our knowledge, none of the articles in the literature investigates the effect of DHP on the CG properties. This work presents a study on the evaluation of the effects of DHP on functional characteristics of CG, including rheological properties, molecular weight, glycosyl-linkage analysis, solubility, swelling and oil absorption capacity (OAC). The results suggest that DHP is able to modify the technological properties of cashew tree gum (increasing solubility and decreasing apparent viscosity).