Abstract Sweet potatoes (SP) have gained attention in the media as foods recommended for healthy diets. When preparing the roots for consumption, however, cooking methods do alter their chemical, physical and nutritional properties. In order to assess the changes in carbohydrates of four SP accessions, after common cooking treatments (pressure cooker, convection oven and microwave oven), the contents of sugars and total starch, as well as the starch digestibility were evaluated. The pressure-cooked and convection oven-cooked samples showed high levels of both total reducing sugars (TRS) and soluble reducing sugars (SRS). Among the samples, white pulp sweet potatoes showed the highest starch contents. When cooked by microwave oven without adding water the roots had higher contents of resistant starch (RS). The results demonstrate deep transformations in the carbohydrate profile after cooking, with increase in maltose levels and consequent reduction in starch levels.

Abstract Resistant starch (RS) has gained interesting because of its health benefits as the control of diseases, such as diabetes. Modifications in starches have been applied in order to increase RS content and consequently the range of industrial food applications. The heat-moisture treatment (HMT) combined with the addition of organic acids was the aim of this study, and also to evaluate the in vitro digestibility and other properties of corn starches. In both botanical sources, the RS content increased significantly, for the normal type and the waxy. Among organic acids used, citric, followed by lactic and acetic acid, promoted the most evident alterations and showed promising results in the increasing of RS. The results obtained by this combined method open opportunities for further applications in functional foods as well as starch based encapsulation process.

Abstract The combination of flours from cereal and legume results in less caloric products, with high contents of fiber, proteins, ash and antioxidants. Thus, this study aimed at developing muffins made with different proportions of wholemeal rye flour (WRF) and wholemeal common black bean flour (WBF). Physicochemical and physical analyses were performed to characterize starches, flours and the muffins. Sensory analysis was also carried out. WRF had the highest values for L* value, moisture and ash contents, whereas WBF had more proteins and lipids, and heterogeneous particle size distribution. The formulation with the highest acceptability grade with total replacement of whole wheat flour, was that containing 70% WRF and 30% WBF (F2). This sample was characterized as high-quality muffin, chocolate flavor, chocolate odor, light and soft crumb. Its texture was defined as low hardness, chewiness and high cohesiveness. It was concluded that the F2 formulation had a high dietary fiber content (20%), low lipid content (8%), containing 32% resistant starch, 9% protein and 51.43 mg GAE 1001 g-1 of total phenolic content, being considered an excellent nutritional food option.

Abstract Starch is an important energy reserve polysaccharide for vegetables, found in large quantities in nature. From a renewable and low-cost source, it is considered an excellent raw material for the production of biopolymers. Biodegradable films can be obtained from different starch sources and can be an alternative to the damages caused by petroleum products, since they have the properties of conventional plastics and are easily degraded in the environment. However, starch-based films have limitations such as poor mechanical properties. To overcome this weakness, the addition of secondary additives is used to improve its resistance. This review highlights how different materials used in the production of biodegradable polymers, the importance of incorporating reinforcement content in the polymer matrix and as the main characterization techniques of bio composites.

Abstract After natural fermentation and solar drying, sour cassava starch acquires expansion property. Traditionally, solar drying occurs without protection, and consequently physical contamination can arise. Thus, the aim of this study was to produce sour cassava starch using a low-cost solar dryer to prevent contamination, whilst retaining the expansion property. The samples were characterized in relation to chemical composition, microscopy and physical contaminants, as well as expansion, thermal, pasting, structural and technological properties. In addition, biscuits were prepared and compared with commercial samples. The solar dryer provided faster drying and lower moisture levels than the control. The specific volumes of the sun-dried products were similar to the control, with minimized contamination. The granules of the starches showed slight erosion on their surface, which was probably due to amylolytic enzymes. X-ray diffraction showed a typical A-type pattern. DSC analysis resulted in higher gelatinization temperatures and enthalpy changes for the sour cassava starch. The pasting properties showed a reduction in the viscosity peak at neutral pH. Although the cassava starch biscuits made with sour cassava starch dried in the solar dryer presented lower expansion levels in relation to the other biscuits produced with commercial sour cassava starch, they had desirable sensory characteristics.

Abstract Sweet potato (SP) starchy roots have a broad range of colors, high-quality nutritional composition including bioactive substances (anthocyanins and β-carotene), vitamins, minerals, dietary fiber and starch. Several studies report the versatility of this root crop as part of the human diet and its possible health benefits. In this review the SP chemical composition, nutritional properties and its potential use in food processing for developing nutritious and healthy products are explored. Due to the adaptation of sweet potatoes to several agricultural managing conditions, accepting low technology /low cost with reasonable performance, it has called attention as a strong candidate of accessible functional food market.

Abstract Slowly digestible starch (SDS) and resistant starch (RS) associate with health benefits when present in the diet. This study aimed to evaluate ready-to-eat corn and cassava flours regarding their commercial presentation (dry or flaked), composition and in vitro digestibility of starch. Sixteen samples from Southern Brazil were procured in the market: eight dry cassava flours, six biju-type (flaked) corn flours and two biju-type cassava flours. Dry cassava flours had higher L* and lower b* values, and higher RS, relative crystallinity and viscosity peak values. Dry cassava flour partially preserves granular starch, as its processing involves lower drying temperatures and lower moisture of the pressed pulp. Dry cassava flours that had higher b* values also had higher rapidly digestible starch (RDS) levels, since higher temperatures are required in their production. Both biju-type flours showed the highest RDS values and no RS due to processing with elevated temperature and high moisture of the pressed pulp. In this study starch digestibility from the flours depended on processing, with minor influence of the raw material, fiber content and granulometry. The whiter and the smaller the granulometry of the dry cassava flours, the better they showed as potentially health benefiting.

Abstract The consumption of yerba mate beverages is related to several health benefits. These desirable properties are mainly due to the bioactive compounds. However, the levels of those compounds are directly affected by factors such as geographical origin. This study aimed to use chemometrics to evaluate the antioxidant compounds of yerba mate (consumed as chimarrão) marketed in southern Brazil. Neochlorogenic acid and caffeine were the main bioactive compounds found in this type of yerba mate beverage (chimarrão). The dataset was analyzed by chemometrics, and principal component analysis using the first three principal components explained 61.30% of the total variance. Hierarchical cluster analysis suggested three clusters, with cluster 1 containing the majority of the samples from the states of Rio Grande do Sul and Paraná, with higher levels of phenolics, methylxanthines, and antioxidant activity. The supervised methods, soft independent modeling of class analogy (SIMCA) and partial least squares-discriminant analysis (PLS-DA), had similar predictability (≥75% of accuracy) in terms of classifying yerba mate according to different Brazilian regions. Therefore, the chemometric tools used in the current study was suitable to monitor and assess a large variation of the antioxidant composition of yerba mate from different southern Brazilian states.

Abstract The ultrasound effect on functional and structural properties of hydrolysates of different bovine collagens (fibers, gelatines and hydrolysates) was evaluated. The enzymatically hydrolyzed samples (enzyme Alcalase®) with previous or simultaneous ultrasound treatment presented higher number of bands with shorter wavelengths (mid-FTIR). The ultrasound provided the samples with a higher hydrolysis degree and favored the antimicrobial activity, evidencing the advantages of its use in the process. Results revealed that higher hydrolysis degree does not always result in higher antioxidant activity. The use of ultrasound in the hydrolysis of these samples was seen to be effective, providing them with higher functionality and structural disruption.

Abstract Obtaining collagen and hydrolysates from mechanically separated chicken meat residue is an excellent way to add value to this waste. The aims of this study were to obtain collagen hydrolysates from chicken MSM residue using Alcalase® and Flavourzyme® enzymes, as well characterizing the functional, structural and thermal stability properties. The highest degree of hydrolysis was obtained using Alcalase®, 36.11%, while using Flavourzyme® resulted in 12.02%. The DSC analysis of the collagen indicated a denaturation temperature of 46.47 °C. The FTIR spectra of the crude collagen showed absorption peaks that were characteristic of amide bands A, B, I, II and III. In the spectra of the hydrolysed the area of the amide bands was reduced, and some peaks appeared between 800 and 1,200 cm-1. The disappearance of high molecular weight bands in the SDS-PAGE analysis also confirmed the hydrolysis of collagen. After the hydrolysis, the collagen presented reduced viscosity, the capacity to form foam, and foam stability. The emulsifying activity index was high in the hydrolysates in relation to the crude collagen. Thus, the use of Alcalase® and Flavourzyme® to obtain hydrolysates from collagen derived from chicken MSM residue was shown to be viable, and potentially useful for industrial applications.

Abstract Biodegradable films were prepared using regular and waxy starch and reinforced with cellulose nanofibers (CNF) from eucalyptus. Both films were characterized by their optical, structural, barrier, thermal and mechanical properties. The films presented a homogeneous, smooth surface without bubbles or cracks and good handling characteristics. Both films showed a mixture of B and V-type diffraction patterns. The water solubility of the samples decreased after the incorporation of nanocellulose. The water vapor permeability for both sources significantly reduced after incorporating nanocellulose at 0.5% and 1%. It is possible to observe that the addition of CNF increased the thermal stability of the starch films. On the other hand, the incorporation of nanocellulose improved either the mechanical resistance of the starch films.

RESUMO: No Brasil, não há uma regulamentação técnica específica sobre a identidade e qualidade de queijos maturados com mofo branco na superfície. Estes queijos são comercializados inteiros (tipo Camembert) e em cunhas (tipo Brie). O objetivo da pesquisa foi avaliar as propriedades físicas e químicas; parâmetros tecnológicos e marcadores microbiológicos de 20 queijos inteiros (tipo Camembert) e 16 cunhas de queijo (tipo Brie) produzidos no Brasil. Os teores de sódio e cálcio apresentaram elevada amplitude (8,0 e 4,6 vezes o valor mínimo, respectivamente). Os valores médios destes queijos não apresentaram diferenças significativas em relação à maioria dos parâmetros analisados. Listeria monocytogenes foi encontrada em 5% das amostras de queijo tipo Camembert. Os demais parâmetros microbiológicos estavam de acordo com a legislação vigente, RDC no 12/2001 da Anvisa. Esta avaliação comparativa entre estes dois queijos indica que são diferentes. Além disso, os valores com elevada amplitude correspondem a falta de padronização do processamento. Os valores médios poderiam ser considerados como recomendados para estes queijos no Brasil.

ABSTRACT: There are no specific technical regulations regarding the identity and quality of white mold surface-ripened cheeses in Brazil. These cheeses are sold both whole (Camembert-type) and in wedges (Brie-type). The aim of the study was to evaluate the physical and chemical properties; technological parameters and microbiological safety of 20 whole cheeses (Camembert-type) and 16 cheese wedges (Brie-type) produced in Brazil. Samples showed a wide range in sodium (91.0-731.0 mg/100 g, cheeses wedges) and calcium (238.0-1100.0 mg/100g, whole cheeses) contents. The cheese groups presented no significant differences in relation to the majority of the analyzed parameters. Listeria monocytogenes was reported in 5% of the whole cheese samples. The other microbiological parameters were in accordance with the current legislation, RDC no 12/2001 of Anvisa. The comparative assessments between these two cheeses indicated that they are different. In addition, the wide range of results indicated a lack of processing standardization. The mean values of the physicochemical and textural parameters should be considered as recommended for these cheeses in Brazil.

Abstract A new type of ripened soft cheese by Geotrichum candidum was manufactured with pasteurized milk from Jersey and Holstein cow breeds. The physico-chemical (moisture, pH, acidity, protein, lipids and ash) and technological parameters (proteolysis, texture profile and color) during 21 days of ripening cheese (surface, center and whole), were evaluated. The differences in the cheese produced with Holstein cow milk were related to increased proteolysis (tyrosine and acid-soluble nitrogen) and the influence of the a* and b* color parameters. The cheeses prepared with Jersey cow milk showed a high fat content and lower proteolysis, which had a significant effect on the instrumental texture profile. Using chemometrics and two-way ANOVA was possible to distinguish the cheeses based on the breed of cow and ripening time. After two weeks, the cheeses already presented characteristics of the ripening by G. candidum.

Abstract Ginger and white yam starches were investigated and compared with maize starch. Proximal composition, thermogravimetry, differential scanning calorimetry, microscopy, colourimetry, X-ray powder diffractometry and pasting profile were analysed. The unconventional starches presented higher protein and ash contents than the maize starch, that had the highest thermal stability. Higher gelatinisation temperatures were reported for ginger starch, and the enthalpy of the unconventional starches were similar. The maize starch presented the lowest gelatinisation values. For the corn starch the granules were polygonal and smaller than the unconventional starches, and oval shapes and larger diameters were found for the ginger and yam starches. The unconventional starches presented less brightness and a greater tendency to red and yellow. The maize and ginger starches had A-type diffraction patterns, while the white yam starch had a C-type pattern. The highest relative crystallinity was observed for the ginger starch and there were small differences between the yam and maize starches. Higher peak viscosity and final viscosity and lower pasting temperature were observed for the yam starch. Ginger starch showed the highest shear and stability of heating glue, so may be used in products processed under high temperatures; and yam starch can be used in acidic foods that require high viscosities.

Abstract The effects of gamma radiation (0, 1, 2 and 3 kGy) were used to evaluate the stability and thermal degradation kinetics of anthocyanins, as well as the stability of total phenolic compounds (TPC) and antioxidant activity at different temperatures (4, 25, 35 and 45 °C) during the storage (0, 30, 60, 90 and 120 days) of black rice flour. This flour can be used as ingredient for gluten-free cereal products with higher nutritional value. For this it is necessary to preserve the anthocyanin content during thermal processing and shelf-life periods. At time 0, the dose of 3 kGy provided all of the most available bioactive compounds, raising their antioxidant potential, except for TPC. During the storage at different temperatures up to 120 days, gradual losses occurred in all the analysed parameters. Regarding the total anthocyanin content and TPC, the sample irradiated with a 1 kGy dose remained most stable. The analysis of kinetic data indicated a first-order reaction for the degradation of anthocyanins. The combination of irradiation with different temperatures may improve the shelf-life of black rice flour.