The Effect of Pretreatments on the Physical Properties and Starch Structure of Potato Chips Dried by Microwaves under Vacuum.

Native potato starch has a semi-crystalline structure associated with a low glycemic index. Microwave vacuum drying (MWVD) produces crispy snacks under mild temperatures, reducing starch structural changes. However, blanching pretreatment gelatinizes starch, reducing crystallinity. A promising alternative is drying raw or blanched-then-cooled potatoes by MWVD. Cooling the blanched potato before MWVD aims to promote the partial return of the crystalline structure. Thus, this study evaluated how different pretreatments affect potato chips' starch structure and physical properties. Three samples were dried by MWVD: (i) raw (MWVD-RW), (ii) blanched (MWVD-BL), and (iii) blanched followed by cooling (4 °C for 48 h) (MWVD-BLC) potatoes. MWVD-RW samples presented a higher starch crystallinity (16.9%), which disappeared in MWVD-BL samples and partially returned in MWVD-BLC (8.7%). MWVD-BL and MWVD-BLC samples presented lower bulk (<0.338 g cm−3) density and higher porosity (>74%) and crispness. On the other hand, MWVD-BLC samples presented intermediate characteristics for color, true density, and porous distribution compared to others. All samples showed high porosity (>69%) and crispy texture. Therefore, based on the quality assessment, the MWVD-RW and MWVD-BLC produced healthy and crispy oil-free chips with a potentially lower glycemic index.

Study of the influence of line scale length (9 and 15 cm) on the sensory evaluations of two descriptive methods.

The line scale is widely used in different lengths to quantify the intensity of descriptors in sensory evaluation. Since studies related to its size are still limited the objective was to determine what variables of descriptive sensory evaluation can be influenced when different scale length is considered in two different methods: Optimized Descriptive Profile (ODP) (low degree of training) and Conventional Profile (CP) (high degree of training). Five chocolate samples were evaluated by two panels, one using the 9 cm and the other using the 15 cm line scale. The panels performed the sensory analysis using the ODP and after the CP method. The following criteria were investigated: interaction between sample and evaluator, discriminative capacity, repeatability of results, and frequency of score use on the unstructured scale. The influence of scale length on sensory responses was similar in the two methods (ODP and CP). When comparing the two scales in both methods, it was observed that the 15 cm scale resulted in an improvement in discriminative capacity, reduction of interaction and the evaluators tended to distribute their ratings more evenly across this scale length. The repeatability of results showed a slight tendency to be better on the 9 cm scale.

Otimização da aceitabilidade sensorial de requeijão cremoso light / Optimization of the sensory acceptability of light cream cheesecurd

O requeijão cremoso é um tipo de queijo fundido originalmente brasileiro, fabricado em todo território nacional com algumas variações de tecnologia. Este é um dos principais tipos de queijos produzido e consumido no Brasil e apresenta como característica o elevado teor de gordura. Por outro lado, a gordura apresenta papel fundamental na aparência, sabor e textura de requeijão, portanto desenvolver um produto light com qualidade sensorial semelhante à versão tradicional é um grande desafio à indústria de alimentos. Nesse contexto, o objetivo deste trabalho foi avaliar a composição química e a aceitabilidade sensorial de requeijão cremoso light, com diferentes níveis de redução de gordura, em relação à textura e impressão global. O experimento seguiu um delineamento de superfície de resposta, o Delineamento Composto Central Rotacional (DCCR) com dois fatores (gordura e umidade). A aceitabilidade sensorial foi avaliada por 100 consumidores, utilizando a escala hedônica de nove pontos. Os resultados obtidos demonstraram que os requeijões com diferentes níveis de redução de gordura apresentaram aceitabilidade sensorial semelhante quando combinados a um aumento proporcional do teor de umidade. Os produtos que apresentaram extrato seco desengordurado (ESD) de aproximadamente 19,3 por cento, originados de diferentes combinações entre gordura e umidade, foram os que apresentaram melhor aceitação por parte dos consumidores, demonstrando a importância do ESD na aceitabilidade sensorial.

Cream cheesecurd is a type of processed cheese, originally Brazilian, produced throughout the entire Brazilian territory with some technological variations. This is one of the main types of cheese produced and consumed in Brazil and it is known for presenting an elevated fat content. On the other hand, the fat plays a fundamental role in appearance, flavor and texture of cheese, then developing a light product with sensory quality similar to the traditional version is a major challenge to food industry. In this context, the objective of this study was to evaluate the chemical composition and sensory acceptability of light cream cheesecurd with different levels of fat reduction for texture and overall impression. The experiment followed a design of response surface, the Central Composite Rotatable Design (CCRD) with two factors (fat and moisture). The sensory acceptability was evaluated by 100 consumers, by the hedonic scale of nine points. The results showed that the cheesecurds with different levels of fat reduction had similar sensory acceptability when combined with a proportional increase in moisture content. The products that presented dry defatted extract (DDE) of approximately 19.3 percent, originated from different combinations of fat and moisture, were those with better acceptance by consumers, demonstrating the importance of DDE in sensory acceptance.