The effect of acid hydrolysis on the technological functional properties of pinhão (Araucaria brasiliensis) starch

Investigation of dual modification on physicochemical, morphological, thermal, pasting, and retrogradation characteristics of sago starch

The aim of this study was to evaluate the characteristics of dually modified sago starch by acid hydrolysis (AH)-hydroxypropylation (HP). For this purpose, sago starch was modified with the combination by AH (5-20 h hydrolysis times) followed by HP (5%-25% ratio of propylene oxide) processes. The results showed that the dual modification of the sago starch structure didn't have a significant effect on the size of starch granules, and the granule size was in the range of 0.005-0.151 µm; however, the pasting properties and the glass transition temperature decreased significantly (p < .05). Increasing the level of propylene oxide from 5% to 25% caused a significant increase in the substitution degree (DS) and swelling ability of starches and reduced the syneresis, while with increasing acid hydrolysis time from 5 h to 20 h, starch swelling decreased and syneresis increased (p < .05). AH process at high hydrolysis times (20 h) increased the gelatinization temperatures and decreased retrogradation temperatures. Increasing the level of propylene oxide in both single and dual modification reduced the temperatures and enthalpy of gelatinization and retrogradation of sago starch. In summary, dually modified sago starch has a great potential to use in specific food products such as frozen dough or frozen bakery products.

An Insight into the Gelatinization Properties Influencing the Modified Starches Used in Food Industry: A review

Native starch is subjected to various forms of modification to improve its structural, mechanical, and thermal properties for wider applications in the food industry. Physical, chemical, and dual modifications have a substantial effect on the gelatinization properties of starch. Consequently, this review explores and compares the different methods of starch modification applicable in the food industry and their effect on the gelatinization properties such as onset temperature (To), peak gelatinization temperature (Tp), end set temperature (Tc), and gelatinization enthalpy (ΔH), studied using differential scanning calorimetry (DSC). Chemical modifications including acetylation and acid hydrolysis decrease the gelatinization temperature of starch whereas cross-linking and oxidation result in increased gelatinization temperatures. Common physical modifications such as heat moisture treatment and annealing also increase the gelatinization temperature. The gelatinization properties of modified starch can be applied for the improvement of food products such as ready-to-eat, easily heated or frozen food, or food products with longer shelf life.

Dual modification of achira (Canna indica L) starch and the effect on its physicochemical properties for possible food applications

The aim of this study was to evaluate the effect of acid hydrolysis and succination upon single and a combination of both of them as a dual modification on the morphological, structural, thermal, and pasting profile of the achira starch in order to expand its potential food applications. The surface of achira starch granules was eroded with acid hydrolysis, while the succination resulted in the formation of pores or cavities, having a slight impact on the crystallinity and the gelatinization enthalpy. Succinated starch presented the lowest transition temperatures (To = 60.29 °C, Tp = 65.03 °C and Te = 69.86 °C) compared to other starches in this study. The succination increased the final viscosity (3808 cp) when compared with the native starch (3114 cp), while acid hydrolysis resulted in a decreased value (735 cp). These are desirable properties for its possible use as an additive in bakery industry processes.

Elaboração e caracterização de doce cremoso de caqui com adição de sementes da araucária

Resumo A inovação é um dos pilares para o alcance do desenvolvimento sustentável e, para a inserção de um novo produto alimentício no mercado, abordagens que englobem pesquisas em ciência e tecnologia se fazem necessárias. Visando propor uma alternativa para o uso do pinhão e o aproveitamento de frutos de clima temperado, cultivados no Estado do Paraná, foi elaborado um doce cremoso de caqui, substituindo-se parcialmente a polpa por diferentes concentrações de pinhão nas formulações (0, 5 e 10%). Foram realizadas análises de sólidos solúveis, atividade de água, pH, acidez total titulável, teor de umidade, cinzas, cor e textura, além da caracterização microbiológica dos produtos. Atendendo aos padrões de identidade e qualidade quanto às características físicas, químicas e microbiológicas, a inserção de sementes de pinhão e a consequente redução no teor de polpa promoveram, do ponto de vista tecnológico, o desenvolvimento adequado deste produto inovador. Os valores da atividade de água, a concentração de açúcares e a baixa acidez observados no produto tornaram o ambiente desfavorável ao desenvolvimento de micro-organismos, condições estas associadas às boas práticas de fabricação. A alteração na formulação padrão influenciou na análise instrumental do perfil de textura, devido à presença de amido da semente de pinhão. Os parâmetros de cor apresentaram resultados de baixa luminosidade, o que reporta a produtos pouco translúcidos, o que é característico de alimentos de alto teor de açúcares, concentrados por evaporação. No espaço de cor notou-se a expressão da cromaticidade a* e b*, que apontam para a predominância das cores amarelo e vermelho, característicos do fruto de origem. As investigações abordadas revelam a aplicabilidade tecnológica do pinhão, contribuindo para a agregação de valor através da diversificação de produtos e mostrando-se como uma alternativa para geração de recursos financeiros para pequenos produtores rurais através do extrativismo, garantindo a conservação de espécies da Floresta com Araucária.

Chemical and structural properties of sweet potato starch treated with organic and inorganic acid

In the present study sweet potato starch was treated with hydrochloric acid or citric acid at 1 or 5 % concentration and its properties were investigated. Citric acid treatment resulted higher starch yield. Water holding capacity and water absorption index was increased with increased acid concentration. Emulsion properties improved at 5 % acid concentration. The DE value of acid-thinned sweet potato starches was ranged between 1.93 and 3.76 %. Hydrochloric acid treated starches displayed a higher fraction of amylose. X-ray diffraction (XRD) study revealed that all the starches displayed C-type crystalline pattern with varied crystallinity. FT-IR spectra perceived a slight change in percentage intensity of C-H stretch of citric acid modified starches. Starch granules tended to appear less smooth than the native starch granules after acid treatment in Scanning Electron Micrographs (SEM) with granule size ranging between 8.00 and 8.90 μm. A drastic decrease in the pasting profile was noticed in hydrochloric acid (5 %) treated starch. While 5 % citric acid treated starch exhibited higher pasting profile. Differential Scanning Calorimeter (DSC) showed that peak and conclusion gelatinisation temperatures increased with increase in hydrochloric acid or citric acid concentration. Hence citric acid was found to mimic the hydrochloric acid with some variation which suggests that it may have promising scope in acid modification.