The main objectives of this study were to develop an effective process to produce modified pea starch with enhanced enzyme resistance property (RS) for food applications. The work compares a non-chemical method (heat moisture treatment) versus a chemical method (crosslinking). One type of commercial pea starch (Nutri-Pea) was used exclusively as the raw material in this study. A number of methods were used to characterize the properties of the modified pea starches: water solubility index (WSI), titration (conversion, iodine value), intrinsic viscosity, infrared spectroscopy (FT-IR), Englyst digestion method, total starch content, and rapid visco analysis (RVA). The effects of heat-moisture treatment on native pea starch and enzyme treated pea starch were examined. The results showed that the produced samples with both native starch and enzyme treated starch exhibited a sharp increase in intrinsic viscosity. Overall, this method was deemed undesirable and not extensively examined past preliminary evaluations. The main focus of the study was on a citric acid crosslinking reaction, chosen for its food compliancy. A temperature of 120 oC was considered ideal for the reaction. FT-IR confirmed the presence of the citric acid incorporation in the starch samples. To improve the extent of reaction, Butanetetracarboxylic acid (BTCA) was considered as a replacement for citric acid and its treated samples showed higher conversion and lower water solubility index than that of the citric acid treated samples. Sodium propionate (NaP) was also considered in the reaction, this time as a food-grade catalyst and found to have minor benefit in cross-linking. BTCA/NaP treated sample reached the highest conversion of the study (96.8±2.3 %) and the lowest WSI (13.1±2.0 %), which increased the RS fraction of the starch from 18% to 32%. The RVA pasting profiles examined were too low to compare due to the high degree of cross-linking. Further improvements to RS were sought by debranching the starch before acid crosslinking. A BTCA/NaP treated sample with enzyme treatment showed a low WSI (31.7±2.3 %) yet substantially higher RS fraction (80.81±0.18 %). Similar to the non-debranched acid modified samples, there were no significant RVA pasting results because of the high cross-linking. Finally, crosslinking with an epoxidized oil was tested to continue looking at food-grade solution yet possible increase the rate of the crosslinking reaction. The results of WSI indicated that this method had little influence on cross-linking, possibly due to the low epoxidation efficiency of vegetable oils, as determined by iodine value. / Thesis / Master of Applied Science (MASc)

Made available in DSpace on 2017-07-21T18:53:08Z (GMT). No. of bitstreams: 1 Jose Pedro.pdf: 2190334 bytes, checksum: 091c9d7fac9a1c0a497c54fbd8c1584f (MD5) Previous issue date: 2017-02-20 / Common beans are highly consumed in Brazil, mainly in complement with rice. It is a nutritious food source, riches in carbohydrates that represent 60% of the dry weight of the grains which starch is the largest fraction. Starch is a natural polymer of glucose and it is considered as an energy reserve of the higher vegetables. Found as semicrystalline granules, starch is a mixture of amylose and amylopectin molecules and this one has a greater content. In its native form, starch presents limited application, especially as a binding agent, due their low thermal resistance and high tendency to retrograde. Therefore, physical and/or chemical modifications can be applied in order to improve technological properties, making starch viable at industrial level. The present study aimed to extract bean starch, analyze their physical-chemical and technological properties, modify by oxidation, acetylation and dual-modification, as well as their application in breaded products. The X-ray diffractograms showed that bean starch has a type C, typical of legumes. Images of electron microscopy revealed that the granules has an oval and elliptical shape. The oxidation of the starch was evidenced by the increase of carbonyl and carboxyl contents. Acetylated samples presented a low degree of substitution, that allow food application. Substitution of hydroxyls was proved by acetyl groups that exhibits bands in the region of 1735-1740 cm-1. Modified starches showed changes in their technological properties. Oxidized sample presented increase of the peak and setback viscosity, due carboxylic groups. The acetylated starch presented cooking stability, due their low breakdown viscosity. Enthalpies of gelatinization of the modified samples reduced, in function of weakening of the granular structure. Relative crystallinity, hardness and adhesiveness of the gels, also reduced. Application of bean starch in breaded products exhibited interesting results. The system with oxidized starch resulted in the most crust covered area after frying, 72%. Breaded meat presented yield up to 100%, that means weight gain during the process. The pick-ups values of samples with starch were less than 30%, then the fried products can be classified as breaded. Batter containing oxidized starch resulted in the lowest absorption oil and the highest hardness, which may be associated with the amylose content. The use of modified bean, an unconventional botanical source of starch, proved to be possible due their technological properties and the results of breaded products. / O feijão apresenta alto consumo no Brasil, sendo muito consumido em complemento com o arroz. Trata-se de um alimento nutritivo, rico em carboidratos, que representa 60% da massa seca dos grãos, sendo o amido a maior fração. O amido é um polímero natural de glucose e é considerado como a reserva energética dos vegetais superiores. Este biopolímero apresenta-se como grânulos semicristalinos, sendo uma mistura de moléculas de amilose e amilopectina, essa em maior concentração. Na sua forma nativa, o amido possui aplicação limitada, especialmente como agente ligante, em função de baixa resistência térmica e elevada tendência à retrogradação. Por isso, modificações, biológicas, físicas e químicas, podem ser utilizadas de modo a melhorar as suas propriedades tecnológicas, tornando-o aplicável a nível industrial. O presente trabalho teve como objetivo a extração de amido de feijão, avaliação das propriedades físico-químicas e tecnológicas, modificação por oxidação, acetilação e oxidação seguida de acetilação, além de aplicação em empanados cárneos. Pela análise dos difratogramas de Raios X, o amido de feijão demonstrou padrão do tipo C, típico de leguminosas. As imagens de microscopia eletrônica revelaram que os grânulos apresentaram formato oval e elíptico. A oxidação do amido foi evidenciada pelo aumento nos teores de carbonila e carboxila. As amostras acetiladas apresentaram grau de substituição que permite aplicação em alimentos e a substituição de hidroxilas por grupos acetil foi comprovada por bandas na região de 1735-1740 cm-1. Os amidos modificados exibiram alterações nas suas propriedades tecnológicas. A amostra oxidada apresentou aumento da viscosidade de pico e setback, em função dos grupos carboxílicos. O amido acetilado demonstrou possuir uma estabilidade de cozimento de pasta, por apresentar baixo breakdown. As entalpias de gelatinização das amostras modificadas reduziram, em função do enfraquecimento da estrutura granular, assim como a cristalinidade relativa, dureza e adesividade dos géis. A aplicação dos amidos de feijão nos empanados cárneos apresentou resultados interessantes. O sistema com amido oxidado resultou na maior adesão, com 72% da crosta coberta após a fritura. Os empanados apresentaram rendimento superior a 100%, o que indica ganho de massa durante as etapas de empanamento. Os pick-ups das amostras com amido foram inferiores a 30%, o que faz com que os produtos possam ser classificados como breadered. O batter contendo amido oxidado, resultou na menor absorção e óleo e maior dureza, o que pode estar associado ao teor de amilose. O uso de amido de feijão modificado, uma fonte botânica não-convencional, mostrou-se possível, dada as suas propriedades tecnológicas e resultados da aplicação em empanados.