Physical and structural changes induced by high pressure on corn starch, rice flour and waxy rice flour

• Published in: Food research international Vol. 85; pp. 95 - 103
• Main Authors: Cappa, Carola, Lucisano, Mara, Barbosa-Cánovas, Gustavo V., Mariotti, Manuela
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01-07-2016
• Subjects: Corn; Differential scanning calorimetry; Flour; Gluten-free; High pressure processing; Moisture; Pasting properties; Rice; Scanning electron microscopy; Solvent retention; Solvent retention capacity; Starch; Starches; Ptime; Gluten-free; BD; PT; SCSRC; SRC; PV; HP; H; WRC; SuSRC; WRF; XRD; SB; FV; Tf; BU; T; Tp1; ANOVA; DSC; Tp2; To; LSD; GF; LASRC; Starch; Solvent retention capacity; Flour; Pasting properties; SEA; High pressure processing; CS; RF; ESEM; MVA; TS
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2016.04.018

The impact of high pressure (HP) processing on corn starch, rice flour and waxy rice flour was investigated as a function of pressure level (400MPa; 600MPa), pressure holding time (5min; 10min), and temperature (20°C; 40°C). Samples were pre-conditioned (final moisture level: 40g/100g) before HP treatments. Both the HP treated and the untreated raw materials were evaluated for pasting properties and solvent retention capacity, and investigated by differential scanning calorimetry, X-ray diffractometry and environmental scanning electron microscopy. Different pasting behaviors and solvent retention capacities were evidenced according to the applied pressure. Corn starch presented a slower gelatinization trend when treated at 600MPa. Corn starch and rice flour treated at 600MPa showed a higher retention capacity of carbonate and lactic acid solvents, respectively. Differential scanning calorimetry and environmental scanning electron microscopy investigations highlighted that HP affected the starch structure of rice flour and corn starch. Few variations were evidenced in waxy rice flour. These results can assist in advancing the HP processing knowledge, as the possibility to successfully process raw samples in a very high sample-to-water concentration level was evidenced.
This work investigates the effect of high pressure as a potential technique to modify the processing characteristics of starchy materials without using high temperature. In this case the starches were processed in the powder form - and not as a slurry as in previously reported studies - showing the flexibility of the HP treatment. The relevance for industrial application is the possibility to change the structure of flour starches, and thus modifying the processability of the mentioned products.
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•High pressure (HP) was used to modify corn starch and rice flour physical properties.•HP impact was investigated as a function of applied pressure, temperature and time.•High pressure treatments induced different pasting behaviors and solvent retention capacities.•Raw samples at a high sample-to-water concentration level were fruitfully processed.