The potential exploitation of the Malay-red apple (Syzygium malaccense) seed as source of a phosphorylated starch.

This work presents the characterization of a novel naturally phosphorylated starch extracted from an unconventional and non-utilized source, the seeds of the stone fruit Syzygium malaccense. The morphology and chemical characteristics of the extracted starch were examined by scanning electron microscopy, FTIR, 1H/13C/31P NMR and 13C-CP/MAS-NMR, HPAEC-PAD chromatography, XRD, DSC, and RVA. The extraction yielded a highly pure starch (95.6 %) with an average granule size of 13 µm. The analysis of the starch components revealed an amylose content of 28.1 % and a predominance (65 %) of B-chains (B1-B3 65 %) in the amylopectin, as shown through HPAEC-PAD chromatography. The X-ray diffractogram was compatible with B-type starch, which was confirmed by the deconvolution of the C1 peak in the 13C-CP/MAS-NMR. X-Ray diffractogram also showed that S. malaccense has 28.5 % of crystallinity. DSC analysis showed values of 82.6 °C and -12.41 J g-1 for Tc and ΔH, respectively, which is compatible with a highly ordered starch granule structure. The values observed for peak (4678 mPa•s), trough (3055 mPa•s), and final viscosity (6526 mPa•s) indicated that S. malaccense may be used as a thickener in hot food.

The microstructure of the starch from the underutilized seed of jaboticaba (Plinia cauliflora).

This work presents a starch extracted from jaboticaba seeds. The extraction yielded 22.65 ± 0.63% of a slightly beige powder (a* 1.92 ± 0.03, b* 10.82 ± 0.17 and L* 92.27 ± 0.24). The starch presented low protein content (1.19% ± 0.11) and phenolic compounds (0.58 ± 0.02 GAE. g) as contaminants. The starch granules showed small, smooth, irregular shapes and sizes between 6.1 and 9.6 µm. The starch presented a high content of amylose (34.50%±0.90) and a predominance of intermediate chain length (B1-chains 51%), followed by A-chains (26%) in the amylopectin. The SEC-MALS-DRI showed the starch had a low molecular weight (5.3·106 g·mol-1) and amylose/amylopectin content compatible with a Cc-type starch, confirmed in the X-ray diffractogram. Thermal studies showed a low onset temperature (T0 = 66.4 ± 0.46 °C) and gelatinization enthalpy (ΔH = 9.1 ± 1.19 J g-1) but a high-temperature range (ΔT = 14.1 ± 0.52 °C). The jaboticaba starch proved to be a promising material for food and non-food applications.

Antioxidant and emulsifying properties of a galactose-rich heteropolysaccharide from Plinia cauliflora peels.

In this study functional properties of a galactose-rich heteropolysaccharide (GH) were accessed. The bands of a galactose-rich polysaccharide were found in FTIR spectra, including those from the fingerprint region. GH was characterized as a dark-red material (L* 25.86 ± 0.75, a* 9.46 ± 1.01, b* 0.65 ± 0.14, Chroma 9.48 ± 1.02) with antioxidant activity of 21.5 ± 0.08, 12.1 ± 0.06 and 0.46 ± 0.04 mmol Trolox Eq/mg GH in FRAP, DPPH and ABTS, respectively. GH presented 44.9% of esterification degree and 10.73 ± 0. 01 mg of GAE/g. The production parameters of GH emulsions (GH concentration, time and ultrasound power) were optimized using a 23 Central Composite Rotatable Design (CCRD). Emulsion droplets presented particle size (d µm) varying from 0.823 ± 0.065 to 1.926 ± 0.151, polydispersity index (PDI) from 0.10 ± 0.05 to 0.40 ± 0.01 and zeta potential from -29.25 ± 3.98 to -33.75 ± 1.77. Finally, the high emulsifying activity (EA) (96.67%) and emulsion stability (ES) (97.44%) allow suggesting that GH is a promising polysaccharide for food applications.

Morphological and physicochemical characterization of starches from underground stems of Trimezia juncifolia collected in different phenological stages.

In this study, starches from underground stems of Trimezia juncifolia were evaluated during dry season (DSS), wet season (WSS) and sprouting (SS). Results evidenced that drought stress did not interfere with the yield, amylose content and degree of polymerization (DP) of amylopectin. However, the extraction yield in SS was 58% lower, being observed and increase of 7.5% in the content of amylose, and 13.5% in DP values for SS amylopectin, with a predominance of A-chains. The amount of total sugar, the starch granules size as well as solubility and swelling properties varied as function of the phenological status. Also, starch granules changed from A-type polymorph in DSS and SS to a CA-type in WSS. Nevertheless, it was observed a crystallinity reduction from 56% in DSS to 37.1% in SS. In addition, thermograms evidenced the presence of amylose-lipid complexes, with endothermic transition temperatures being affected by drought stress and sprouting. Finally, results demonstrate that underground stems from T. juncifolia have adaptative strategies involving changes in the morphological and physicochemical properties of the starch granules.

Effect of drought stress on the morphological and physicochemical properties of starches from Trimezia juncifolia.

In this study corms from Trimezia juncifolia were collected in the wet (WSS) and dry (DSS) seasons and used for extraction of starch. Results evidenced that drought stress interfered with the yield, morphological and physicochemical properties of the starches. In addition, it was observed a higher content of amylose for DSS (44%) when compared with WSS (41%). Drought stress did not interfere with the degree of polymerization (DP) of amylopectin, whereas decreased the amylose DP for DSS. Also, starch granules changed from A-type polymorph in the DSS to a CC-type in WSS. Drought stress reduced the starch crystallinity from 27% in WSS to 25.9% in DSS. In addition, the endothermic transition temperatures and enthalpy change of transition were also affected by drought stress. Finally, results clearly demonstrate that changes in the morphological and physicochemical properties of the starch granules figure as adaptive strategies of T. junciolia to drought stress.