Chitosan-based nanocomposite films with carnauba wax, rosin resin, and zinc oxide nanoparticles.

This work aimed to develop edible emulsion-based barriers in the form of chitosan composite films, with a focus on assessing the impacts of carnauba wax, rosin resin, and zinc oxide nanoparticles on their properties. Six films were produced by casting using chitosan as polymer base and glycerol as plasticizer. Acetic acid and polysorbate 80 were also used to facilitate the dissolution and mixing of the components. The six filmogenic solutions contained chitosan at 1.2% w/v, wax or resin content with 0 or 0.6% m/v and ZnO with 0 or 0.05% m/v. The dried films were characterized according to their chemical, barrier, mechanical, thermal and optical properties. All treatments resulted in flexible films. Chitosan films appeared smoother and more uniform under SEM imaging, while carnauba wax films displayed roughness due to their hydrophobic nature. Wax and resin films were less transparent and water soluble than the chitosan-only films. On the other hand, the addition of ZnO in the formulations increased the solubility of the films. The sorption degree was in line with the solubility results, i.e., films with ZnO presented higher sorption degree and solubility values. All treatments showed low or non-light UV transmission, indicating that the films provide good barrier to UV light. In the visible light region, films of resin with ZnO showed the lowest transmittance values, hence offering a good barrier to visible light. Among the evaluated films, chitosan, and resin films with ZnO nanoparticles were more rigid and resistant to deformation. Overall, films produced with rosin resin and ZnO nanoparticles showed potential improvements in barrier, mechanical, thermal, and optical properties, mainly due to their low water solubility, good UV protection and low permeability to water vapor and oxygen, which are suitable for using in formulations, intended to produce edible films and coatings.

Green banana (Musa ssp.) mixed pulp and peel flour: A new ingredient with interesting bioactive, nutritional, and technological properties for food applications.

This study aimed to characterize and evaluate the in vitro bioactive properties of green banana pulp (GBPF), peel (GBPeF), and mixed pulp/peel flours M1 (90/10) and M2 (80/20). Lipid concentration was higher in GBPeF (7.53%), as were the levels of free and bound phenolics (577 and 653.1 mg GAE/100 g, respectively), whereas the resistant starch content was higher in GBPF (44.11%). Incorporating up to 20% GBPeF into the mixed flour had a minor effect on the starch pasting properties of GBPF. GBPeF featured rutin and trans-ferulic acid as the predominant free and bound phenolic compounds, respectively. GBPF presented different major free phenolics, though it had similar bound phenolics to GBPeF. Both M1 and M2 demonstrated a reduction in intracellular reactive oxygen species (ROS) generation. Consequently, this study validates the potential of green banana mixed flour, containing up to 20% GBPeF, for developing healthy foods and reducing post-harvest losses.

Effects of whey protein concentrate, feed moisture and temperature on the physicochemical characteristics of a rice-based extruded flour.

The influence of whey protein concentrate (WPC), feed moisture and temperature on the physicochemical properties of rice-based extrudates has been investigated. WPC (0.64-7.36g/100g rice) was extruded under 5 moisture (16.64-23.36g/100g) and 5 temperature (106.36-173.64°C) established by a 32 central composite rotational design. Physicochemical properties [color, porosimetry, crystallinity, water solubility and absorption, pasting properties, reconstitution test, proximate composition, amino acids, minerals and electrophoresis] were determined. WPC and feed moisture increased redness, yellowness and decreased luminosity. Feed moisture and temperature increased density and total volume pore. WPC and moisture increased crystallinity, but only WPC increased solubility and decrease the retrogradation tendency. Increasing temperature increased the viscosity of the extrudates. The addition of WPC improved the nutritional composition of the extrudates, especially proteins. It is suggested that the extrusion process positively affected the retention of most of the polypeptides chains.

Efeito do ultrassom na extração e modificação de amidos / Effect of ultrasound on the extraction and modification of starches

RESUMO: O ultrassom é considerado uma tecnologia limpa, por possibilitar menor gasto de energia, de substâncias químicas e menor geração de efluentes. Além disso, proporciona menor tempo de processamento e reduz a necessidade de aplicação de calor em vários processos. Por isso, tem sido alvo de pesquisa e desenvolvimento na indústria de alimentos, tanto para substituir, quanto para aperfeiçoar ou acelerar técnicas convencionais de processamento. Dentre as diferentes possibilidades de utilização na indústria de alimentos, o ultrassom pode ser considerado uma alternativa para substituir ou reduzir a utilização de substâncias químicas em processos de extração ou modificação de amidos. Quando utilizado na extração, possibilita maior pureza do amido obtido. Já na modificação, algumas alterações nos grânulos de amido podem ser provocadas pelo ultrassom, mas dependem da origem botânica, da composição do amido, dos parâmetros do equipamento e das condições de processamento.

ABSTRACT: Ultrasound is considered a clean technology, because it allows lower energy and chemicals compounds consumption as well as lower generation of waste. Furthermore, it provides shorter processing time and reduces the need for heat application in various processes. Therefore, this technology has been studied in the food industry to replace, improve or accelerate conventional processing techniques. Among the different possibilities of use in the food industry, ultrasound might be considered as an alternative to replace or reduce the use of chemicals during the extraction processes or modification of starches. When used in the starch extraction allows a greater purity of the final product. Towards the modification some changes in the starch granules can be caused by ultrasound, but it depends on the botanical source and starch composition, equipment's parameters and processing conditions.

Benefícios e perigos do aproveitamento da casca de maracujá (Passiflora edulis) como ingrediente na produção de alimentos / Benefits and risks of using passion fruit peel (Passiflora edulis) as an ingredient in food production

A produção do maracujá amarelo cresce no Brasil e o descarte inadequado das cascas representa tanto umproblema para o meio ambiente, como a perda de ingrediente rico em fibras. O seu uso é fonte de rendapara o produtor rural. Esta revisão traz os estudos que têm sido realizados sobre o aproveitamento da cascado maracujá, considerando-se os aspectos nutricionais e, também, uma alternativa segura, em termostoxicológicos, para o aproveitamento desse resíduo. Muitos autores avaliaram a casca do maracujá edetectaram teores de fibra alimentar de 35 a 90 %; e os benefícios do seu consumo foram identificados pormeio de testes in vivo em ratos e em humanos. Em função de interesse, incentivou-se o desenvolvimentode produtos enriquecidos em fibra alimentar utilizando esse resíduo como componente da formulação. Hámuito tempo foram identificados glicosídeos cianogênicos no maracujá, exceto nas sementes. Os efeitostóxicos de alimentos com cianogênicos são observados em países africanos, onde é comum o consumoda mandioca brava sem o tratamento adequado. O processo de extrusão termoplástica tem sido estudadocomo ferramenta útil na redução de substâncias tóxicas e sua utilização será importante para processar ascascas e reduzir cianogênicos aos níveis aceitáveis pela legislação.

Determinação da cor, imagem superficial topográfica e ângulo de contato de biofilmes de diferentes fontes de amido / Determination of color, topographic superficial image and contact angle of the biofilms of different starch sources

Atualmente, um dos problemas que acometem o meio ambiente é a poluição ocasionada pelo descarte de filmes plásticos de polímeros sintéticos sem nenhum controle. Uma das alternativas para minimizar este problema é a utilização de amido na elaboração de materiais biodegradáveis que possuem alta degradabilidade quando lançados no meio ambiente. Apesar do número crescente de trabalhos de pesquisas utilizando diferentes materiais biodegradáveis, o conhecimento das propriedades físicas de biofilmes elaborados com amido ainda é bastante reduzido. Objetivou-se com este trabalho determinar a diferença de cor, a imagem superficial topográfica por microscopia eletrônica de varredura e o ângulo de contato de biofilmes elaborados com três diferentes tipos de amido: filme de fécula de batata (FFB), filme de fécula de mandioca (FFM) e filme de amido de milho (FAM) com três concentrações: 1, 2 e 3 por cento empregando-se um delineamento inteiramente casualizado com três repetições. A interação concentração e tipo de amido foi estatisticamente significativa para ângulo de contato e não significativa para a diferença de cor. A diferença de cor foi afetada pela fonte de amido e o maior valor observado para filme de fécula de mandioca. Com o aumento da concentração de amido, o ângulo de contato diminuiu para filmes de fécula de mandioca e de batata, diferentemente para os biofilmes de milho, onde esta relação foi constante.

Nowadays, the pollution has considerably increased by the large amount of the non-degradable synthetic plastics that is discarded everyday in the environment. One of the alternatives that could contribute to minimize this problem would be the use of the starch as main composite in biodegradable films also called biofilms; in other words, this material is easily degradable when disposed in the environment. Despite the growing number of the scientific papers there is a lack of knowledge of the physical properties of starch in biofilms. The aim of this work was to study the color variation, the topographic superficial surface by scanning electron microscopy and the water absorption by contact angle of biofilms produced with three different starch sources: potato starch film (PSF), cassava starch film (CSF) and maize starch film (MSF) with varied concentration: 1, 2 and 3 percent to prepare biofilms using a complete randomize design with three repetitions. The interaction between starch source and concentration was statistically significant for contact angle whereas it was not significant for color. The color difference was affected by starch source being higher for CSF. As concentration increased in biofilms of potato and cassava, the contact angle decreased in contrast to maize biofilms which remained constant.

Obtenção de farinhas mistas pré-gelatinizadas a partir de arroz e bagaço de jabuticaba: efeito das variáveis de extrusão nas propriedades de pasta / Production of pre-gelatinized flours from rice and jabuticaba bagasse: effect of extrusion variables on the paste properties

No presente trabalho estudou-se o efeito da combinação da velocidade de rotação do parafuso (65,9 - 234,1 rpm), da temperatura na terceira zona do barril do extrusor (99,5 - 200,1ºC) e da formulação de farinha de bagaço de jabuticaba (11,59 -28,41 por cento), utilizada como fonte de fibra, nas propriedades de pasta de farinhas mistas pré-gelatinizadas de arroz polido e bagaço de jabuticaba. Foram determinadas a fibra detergente ácido (FDA) e a fibra detergente neutro (FDN) das farinhas cruas e suas misturas. As propriedades de pasta foram determinadas em Analisador Rápido de Viscosidade (RVA). A farinha de bagaço de jabuticaba (FBJ) apresentou altos valores de FDA (21,91 por cento) e de FDN(45,47 por cento) o que contribuiu para aumentar o teor de fibra alimentar das misturas extrusadas (FME). As amostras estudadas apresentaram perfis diferentes de viscosidade de pasta com valores mínimos para FBJ, valores máximos para FAP e valores intermediários para FME. A viscosidade inicial a 25ºC foi fortemente influenciada pela formulação e pela velocidade de rotação do parafuso, seguidas pela temperatura. A viscosidade máxima a 95ºC (VMAX) e a viscosidade final (VFINAL) foram imensamente influenciadas pela formulação e temperatura, seguidas pela velocidade de rotação do parafuso. Ambas aumentaram com a elevação da temperatura e diminuíram com o incremento da porcentagem de FBJ na mistura, bem como pelo aumento da velocidade de rotação do parafuso.

Características físicas e químicas dos principais cultivares de milho pipoca plantados no Brasil / Physical and chemical characteristics of the main popcorn cultivars grown in Brazil

Fifteen popcorn cultivars grown in Brazil were analysed for expansion power, percent composition, dietary fiber, minerals, vitamins and aminoacids. The mean Expansion Power was 23.1, low for the international standards. The second major component in popcorn is the dietary fiber, ranging from 21 to 29 per cent. Minerals and vitamins are presents in small amounts. Popcorn, like others cereals, is defficient in the limiting aminoacid lysine and triptophan. The popcorn consuption, without addition of other ingredients, can be used in sodium restricted diets, and is a good source for dietary fiber intake

Efeito de farelo de arroz tratado termicamente na vida de prateleira de biscoito tipo amanteigado / Effect of heat-treated rice bran on the shelf-life of butter biscuits

Rice bran was submitted to two heat treatments. In the first treatment, bran was heated in an oven at 105§C for 20 minutes and, in the second treatment, it was heated in a steam autoclave with a pressure of 78456 Pa at 125§C for 20 minutes. The two heated brans were mixed wheat flour at three different levels (O, 10 AND 20 per cent) and these blends were used for the production of biscuits. The biscuit acidity increased with the presence of rice bran in the flour. Biscuits produced with oven-heated bran showed the highest acidity and, the longer the storage time the higher the acidity. It was observed that biscuits which had rice bran in their formulation presented a higher moisture content, which did not vary with storage possibly due to the packaging. Members of the taste panel were able to perceive differences between biscuits which contained bran produced by the two different heat treatments. Biscuits produced with the oven heated bran were darker. Also, they presented unpleasant smell and taste. The other biscuits, produced with the other formulations, obtained intermediate scores in relation to the ones produced just with wheat flour. The results show that the use of rice bran for biscuits-making is practicable and that it could be easily used in biscuits commercial production

Efeito da incorporaçäo de farelo de arroz tratado termicamente sobre as características reológicas da farinha de trigo / Effects of the incorporation of heat treated rice bran on the rheological characteristics of wheat flour

Rice bran submitted to two heat treatments: heated in oven (105§C/3h and in autoclave (125§C/20min at 78456 Pa). The two treated rice brans were blended with wheat flour at 10 and 20 per cent level, and evaluated rheologically, using the Frarinograph, the Amilograph, the Extensiograph and the Falling Number Test. The blend with rice bran heated in oven showed to be the darkest one, at any level of blending. The roce bran increased the pasta viscosity, the retrogradation rate, and weakened the dough, although it did not increased the water absorption of the dough