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Volume 14, Issue 1, 2025
Online ISSN: 2182-1054
Volume 14 , Issue 1, (2025)
Published: 31.07.2025.
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Contents
18.10.2013.
Original scientific paper
Effect of antimicrobial on mechanical, barrier and optical properties of corn starch based self-supporting edible film
Antimicrobials like potassium sorbate, sodium propionate, and benzoic acid were incorporated in corn starch based formulation to investigate their effect on mechanical, water vapour barrier and optical properties of the developed self supporting edible film. The film was prepared by casting technique.When incorporated at 1.40% and above, potassium sorbate decreased the tensile strength (about 22%) and increased the elongation (about 55%) of control film; whereas, it increased the water vapour permeability by 15% only when added at 2.66%. At 2.66%, benzoic acid reduced the tensile strength by 24% and sodium propionate increased elongation by 17%. These two antimicrobials did not change the water vapour permeability. However, all the three antimicrobials adversely affected the optical properties by decreasing the whiteness index, increasing yellowness index, and reducing the surface gloss, with potassium sorbate showing the maximum effect. Among the three antimicrobials, sodium propionate appeared to be the best with minimum deterioration of film properties.
Tanima Chowdhury, Madhusweta Das
01.12.2012.
Professional paper
The impact of cold chain temperature abuses on the quality of frozen strawberries (Fragaria ×ananassa)
The quality of frozen foods can be negatively affected if improper storage and distribution temperatures are allowed. The objective of this study was to investigate the effect of freeze-thaw cycles, which may occur in the cold chain, on colour (Lab, Total Colour Differences (TCD), chroma and hue angle) and vitamin C (ascorbic and dehydroascorbic acids) content of frozen strawberries (Fragaria ×ananassa, Duschesne, cv. Selva). A plan of temperature abuses (TAs) was established, based on a real situation, and applied to frozen strawberries during a four month frozen storage period. The results showed that the lightness (L) was the only parameter that was not significantly affected by range of TAs studied. The colour showed some variation on the parameters a, b, TCD, chroma and hue angle. During TAs, ascorbic acid decreased about 75% and dehydroascorbic acid increased 73%. The non-abused strawberry samples showed better overall appearance than the abused samples.This work contributes to an understanding of the quality changes of frozen strawberries that might occur during frozen storage and cold chain distribution.
Rui Cruz, Margarida Vieira, Cristina Silva
01.12.2011.
Original scientific paper
Challenges in Food Scientist Training in a global setting
Education and training were an integral part of the MoniQA Network of Excellence. Embedded in the "Spreading of excellence programme", Work Package 9 (Joint education programmes and training tools) was responsible for establishing a joint training programme for food safety and quality within and beyond the network. So-called `MoniQA Food Scientist Training' (MoniQA FST) was offered to provide technical knowledge on different levels and research management skills as well. Training needs for different regions as well as for different target groups (scientists, industry personnel, authorities) had to be considered as well as developing strong collaboration links between network partners and related projects. Beside face-to-face workshops e-learning modules have been developed and web seminars were organized. In order to achieve high quality training, a quality assurance concept has been implemented. It turned out that these types of training are of high value in terms of bringing together scientists from different regions and cultures of the globe, involving highly qualified trainers as basis for a sustainable network in the future.
Andreas Höhl, Gerhard Schleining, Charlotte Hochgatterer, Wolfgang Kneifel, Velitchka Gotcheva, Angel Angelov, Sian Astley, Maria Saarela
18.10.2012.
Original scientific paper
Characterization of sponge cake baking in an instrumented pilot oven
The quality of baked products is the complex, multidimensional result of a recipe, and a controlled heating process to produce the desired final properties such as taste, colour, shape, structure and density. The process of baking a sponge cake in a convective oven at different air temperatures (160-180-220 °C) leading to the same loss of mass was considered in this study. A special mould was used which allowed unidirectional heat transfer in the batter. Instrumentation was developed specifically for online measurement of weight loss, height variation and transient temperature profile and pressure in the product. This method was based on measuring heat fluxes (commercial sensors) to account for differences in product expansion and colour. In addition, measurement of height with a camera was coupled to the product mass to calculate changes in density over time. Finally, combining this information with more traditional measurements gave a better understanding of heat and mass transfer phenomena occurring during baking.
Alain SOMMIER, Elisabeth Dumoulin, Imen Douiri, Christophe Chipeau
18.04.2012.
Original scientific paper
Effect of Egg White Utilization on the Physico-Chemical and Sensory Attributes of Protein-rich Yoghurt
High protein yoghurt was made from whole milk, fortified with egg white (30% v/v) and skim milk powder at 12% (w/v). Different yoghurt mixes, with albumin content of 15%, 30% and 45% (v/v), were prepared. The control was made from whole milk, fortified with skim milk powder at 12% (w/v). The blended premixes were pasteurized at 74ºC for 4 seconds, cooled and then inoculated with 3% (w/v) Direct Vat Set yoghurt starter culture at 45ºC. After fermentation for 3 hours in a water bath maintained at 46+-1C, product was cooled to 5ºC and then stored for 24 hours. The effect of the fortification on physico-chemical and sensory properties was investigated. Protein content increased to 8.50% at 45% egg white utilization. Susceptibility to wheying was reduced in egg-white fortified samples, without signicant difference in sensory attributes of the test samples compared to the control. Sensory analysis showed that yoghurt fortified with 45% egg white was organoleptically acceptable. The yoghurt was rated as having better sensory appeal as compared to the control.
Lilian A Gogo, Kennedy O. Gogo, Peter L. Shalo, Symon Mahungu
18.04.2012.
Original scientific paper
Moisture Adsorption and Thermodynamic Properties of California Grown Almonds (Varieties: Nonpareil and Monterey)
Moisture adsorption characteristics of California grown almonds (Nonpareil: pasteurized and unpasteurized almonds; Monterey: pasteurized, unpasteurized and blanched almonds) were obtained using the gravimetric method over a range of water activities from 0.11 to 0.98 at 7-50ºC. The weights of almonds were measured until samples reached a constant weight. The relationship between equilibrium moisture content and water activity was established using the Guggenheim-Anderson-de Boer model. The diffusion coefficient of water in almond kernels was calculated based on Ficks second law. The monolayer moisture value of almonds ranged from 0.020 to 0.035 kg H2O kg-1 solids. The diffusion coefficient increased with temperature at a constant water activity, and decreased with water activity at a constant temperature. The thermodynamic properties (net isosteric heat, differential enthalpy and entropy) were also determined. The net isosteric heat of adsorption decreased with the increasing moisture content, and the plot of differential enthalpy versus entropy satisfied the enthalpy-entropy compensation theory. The adsorption process of almond samples was enthalpy driven over the range of studied moisture contents.
Li Zuo Taitano, Paul Singh
18.04.2012.
Original scientific paper
Kinetics of Hydrolyzing Isolated Soy Protein by an Endopeptidase and its Conceptual Application in Process Engineering
A response study and the effects of different parameters (pH, temperature and enzyme dose) on kinetics of isolated soy protein hydrolysis by a trypsin-like endopeptidase (TL1) were conducted. Degree of hydrolysis (%DH) data varied at different times under different hydrolysis conditions. Fitting the kinetics data to Michaelis-Menten kinetics model did not result in reasonable kinetic parameters, which implied that Michaelis-Menten kinetics was invalid for such a hydrolysis process. A kinetics model proposed by (Gonzalez-Tello, Camacho, Jurado, Paez, & Guadix, 1994) was found to fit the kinetics curve well and resulted in acceptable model parameters. A simple simulation example was performed to demonstrate the concept of how the kinetics equation could be applied in process engineering.
zebin wang, Jason Lombardi, Jessica Shaffer, Ted Wong
01.12.2011.
Professional paper
Nanotechnology: the word is new but the concept is old. An overview of the science and technology in food and food products at the nanoscale level
Brian C. Bryksa, Rickey Y. Yada
01.12.2011.
Professional paper
Changes and Perspectives in Food Studies
Elisabeth Dumoulin
01.12.2011.
Professional paper
Characterization of sponge cake baking in an instrumented pilot oven
Alain Sommier, Elisabeth Dumoulin, Imen Douiri, Christophe Chipeau