Resistant starch contents of native and heat-moisture treated jackfruit seed starch.

Native jackfruit seed starch (JFS) contains 30% w/w type II resistant starch (RS2) and can potentially be developed as a new commercial source of RS for food and pharmaceutical application. Heat-moisture treatment (HMT) was explored as a mean to increase RS content of native JFS. The effect of the conditions was tested at varied moisture contents (MC), temperatures, and times. Moisture levels of 20-25%, together with temperatures 80-110°C, generally resulted in increases of RS amount. The highest amount of RS (52.2%) was achieved under treatment conditions of 25% MC and 80°C, for 16 h (JF-25-80-16). FT-IR peak ratio at 1047/1022 cm(-1) suggested increases in ordered structure in several HMT-JFS samples with increased RS. SEM showed no significant change in the granule appearance, except at high moisture/temperature treatment. XRD revealed no significant change in peaks intensities, suggesting the crystallinity within the granule was mostly retained. DSC showed increases in T g and, in most cases, ΔT, as the MC was increased in the samples. Slight but significant decreases in ΔH were observed in samples with low RS, indicating that a combination of high moisture and temperature might cause partial gelatinization. HMT-JFS with higher RS exhibited less swelling, while the solubility remained mostly unchanged.

Efecto de la acetilación y oxidación sobre algunas propiedades del almidón de semillas de Fruto de pan (Artocarpus altilis) / Effect of acetylation and oxidation on some properties of Breadfruit (Artocarpus altilis) seed starch

El almidón extraído de las semillas del fruto de pan (Artocarpus altilis) fue modificado químicamente por acetilación y oxidación, y sus propiedades funcionales evaluadas y comparadas con las del almidón nativo. El análisis proximal reveló que los almidones modificados presentaron contenidos de humedad más altos que el nativo. El contenido de cenizas, proteínas, fibra cruda, y amilosa aparente fue reducido con las modificaciones. Las modificaciones no alteraron la morfología de los gránulos de almidón nativo de A. altilis, presentando forma irregular, en su mayoría ovalados y con superficie lisa. La absorción de agua, poder de hinchamiento y sólidos solubles variaron con las modificaciones químicas realizadas, resultando mayores en el almidón acetilado. En comparación con el almidón nativo, los dos tipos de modificación redujeron la temperatura inicial de gelatinización; el pico de máxima viscosidad se redujo en el almidón oxidado pero aumentó en el acetilado; la viscosidad de la pasta en caliente disminuyó para los almidones modificados, mientras que la viscosidad en frío fue menor en el almidón oxidado y mayor en el almidón acetilado. La estabilidad se incrementó con la acetilación y se redujo con la oxidación. El almidón acetilado presentó el valor más bajo de setback o asentamiento, por lo que hubo una menor tendencia a la retrogradación.

Effect of acetylation and oxidation on some properties of Breadfruit (Artocarpus altilis) seed starch. Starch extracted from seeds of Artocarpus altilis (Breadfruit) was chemically modified by acetylation and oxidation, and its functional properties were evaluated and compared with these of native starch. Analysis of the chemical composition showed that moisture content was higher for modified starches. Ash, protein, crude fiber and amylose contents were reduced by the modifications, but did not alter the native starch granules’ irregularity, oval shape and smooth surface. Acetylation produced changes in water absorption, swelling power and soluble solids, these values were higher for acetylated starch, while values for native and oxidized starches were similar. Both modifications reduced pasting temperature; oxidation reduced maximum peak viscosity but it was increased by acetylation. Hot paste viscosity was reduced by both modifications, whereas cold paste viscosity was lower in the oxidized starch and higher in the acetylated starch. Breakdown was increased by acetylation and reduced with oxidation. Setback value was reduced after acetylation, indicating it could minimize retrogradation of the starch.

[Effect of acetylation and oxidation on some properties of breadfruit (Artocarpus altilis) seed starch]. / Efecto de la acetilación y oxidaci6n sobre algunas propiedades del almidón de semillas de Fruto de pan (Artocarpus altilis).

Starch extracted from seeds of Artocarpus altilis (Breadfruit) was chemically modified by acetylation and oxidation, and its functional properties were evaluated and compared with these of native starch. Analysis of the chemical composition showed that moisture content was higher for modified starches. Ash, protein, crude fiber and amylose contents were reduced by the modifications, but did not alter the native starch granules' irregularity, oval shape and smooth surface. Acetylation produced changes in water absorption, swelling power and soluble solids, these values were higher for acetylated starch, while values for native and oxidized starches were similar. Both modifications reduced pasting temperature; oxidation reduced maximum peak viscosity but it was increased by acetylation. Hot paste viscosity was reduced by both modifications, whereas cold paste viscosity was lower in the oxidized starch and higher in the acetylated starch. Breakdown was increased by acetylation and reduced with oxidation. Setback value was reduced after acetylation, indicating it could minimize retrogradation of the starch.

Physicochemical properties of Venezuelan breadfruit (Artocarpus altilis) starch.

Artocarpus altilis, seedless variety, is a fruit-producing plant which is cultived in Margarita Island, Venezuela, and is consumed by the inhabitants of the region. Its chemical composition and physical characteristics were determined. The chemical (AOAC and AACC methods), physicochemical, morphometric characteristics, viscoamylographic properties and digestibility in vitro of starch from Artocarpus were studied. The starch yield was 18.5 g/100 g (dw)w with a purity of 98.86%, 27.68 and 72.32% of amylose and amylopectin, respectively. Scanning electron microscopy showed irregular-rounded granules. Swelling power, water absorption and solubility values were determined and found to be higher than that of corn and amaranth starch. The amylographic study showed a gelatinization temperature at 73.3 degrees C, with high stability during heating and cooling cycles. Artocarpus starch could also be categorized in the group of mixed short chain branched/long chain branched glucan starches, this agrees with digestibility results that showed a high degree of digestibility in vitro. These results might be advantageous in medical and food use.