Thermal characteristics and state diagram of freeze-dried broccoli: Freezing curve, maximal-freeze-concentration condition, glass line and solids-melting

Chickpea cooking water (CCW), known as aquafaba, has potential as a replacement for egg whites due to its emulsion and foaming properties which come from the proteins and starch that leach out from chickpeas into the cooking water. High pressure (HP) processing has the ability to modify the functional characteristics of proteins. It is hypothesized that HP processing could favorably affect the functional properties of CCW proteins by influencing their structure. The objective of this study to evaluate the effect of HP treatment on the associated secondary structure, emulsion properties and thermal characteristics of CCW proteins. A central composite rotatable design is used with pressure level (227–573 MPa) and treatment time (6–24 min) as HP variables, and concentration of freeze dried CCW aquafaba powder (11–29%) as product variable, and compared to untreated CCW powder. HP improves aquafaba emulsion properties compared to control sample. HP reduces protein aggregates by 33.3%, while β-sheets decreases by 4.2–87.6% in which both correlated to increasing protein digestibility. α-helices drops by 50%. It affects the intensity of some HP treated samples, but not the trend of bands in most of them. HP treatment decreases Td and enthalpy because of increasing the degree of denaturation.

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Thermal characteristics and state diagram of extruded instant artificial rice

Thermochimica Acta ◽

10.1016/j.tca.2014.08.017 ◽

2014 ◽

Vol 593 ◽

pp. 50-57 ◽

Cited By ~ 15

Author(s):

Heny Herawat ◽

Feri Kusnandar ◽

Dede R. Adawiyah ◽

Slamet Budijanto ◽

Mohammad Shafiur Rahman

Keyword(s):

Thermal Characteristics ◽

State Diagram

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Sorption Isotherm, Glass Transitions and State Diagram for Freeze-dried Plum Skin and Pulp

Food Science and Technology International ◽

10.1177/1082013206065953 ◽

2006 ◽

Vol 12 (3) ◽

pp. 181-187 ◽

Cited By ~ 18

Author(s):

V. R. Nicoletti Telis ◽

P. J. do Amaral Sobral ◽

J. Telis-Romero

Keyword(s):

Glass Transition ◽

Moisture Content ◽

Sorption Isotherm ◽

State Diagram ◽

Transition Curve ◽

Glass Transitions ◽

Water Addition ◽

Scanning Calorimetry ◽

Freeze Dried ◽

The Matrix

Differential scanning calorimetry (DSC) was used to determine phase transitions of freeze-dried plums. Samples at low and intermediate moisture contents, were conditioned by adsorption at various water activities (0.11≤aw≤0.90) at 25°C, whereas in the high moisture content region (aw>0.90) samples were obtained by direct water addition, with the resulting sorption isotherm being well described by the Guggenheim-Anderson-deBoer (GAB) model. Freeze-dried samples of separated plum skin and pulp were also analysed. At aw≤0.75, two glass transitions were visible, with the glass transition temperature (Tg) decreasing with increasing aw due to the water plasticising effect. The first Tg was attributed to the matrix formed by sugars and water. The second one, less visible and less plasticised by water, was probably due to macromolecules of the fruit pulp. The Gordon-Taylor model represented satisfactorily the matrix glass transition curve for aw≤0.90. In the higher moisture content range Tg remained practically constant around Tg′ (−57.5°C). Analysis of the glass transition curve and the sorption isotherm indicated that stability at a temperature of 25°C, would be attained by freeze dried plum at a water activity of 0.04, corresponding to a moisture content of 12.9% (dry basis).

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