Ghadeer F. Mehyar

Antifungal Effectiveness of Potassium Sorbate Incorporated in Edible Coatings Against Spoilage Molds of Apples, Cucumbers, and Tomatoes during Refrigerated Storage

Predominant spoilage molds of fresh apples, cucumbers, and tomatoes stored at 4 °C were isolated and examined for resistance to potassium sorbate (PS) incorporated in polysaccharide edible coatings. The isolated molds were Penicillium expansum, Cladosporium herbarum, and Aspergillus niger from apples. P. oxalicum and C. cucumerinum were isolated from cucumbers and P. expansium and C. fulvum from tomatoes. Guar gum edible coating incorporated with PS was the most effective mold inhibitor, significantly (P<0.05) reducing the isolated spoilage molds for 20, 15, and 20 d of storage at 4 °C on apples, cucumbers, and tomatoes, respectively. PS incorporated into pea starch edible coating was less effective and selectively inhibited the isolated mold species, causing significant (P<0.05) reduction in mold on apples, cucumbers, and tomatoes counts for 20, 10 to 15, and 15 to 20 d of storage at 4 °C, respectively. The isolated mold species exhibited different resistances to PS incorporated in the edible coatings. The greatest inhibition (2.9 log CFU/g) was obtained with C. herbarum on apples and the smallest (1.1 log CFU/g) was with P. oxalicum on cucumbers and the other isolated mold species exhibited intermediate resistance. The coatings tested, in general, inhibited molds more effectively on apples than on tomatoes and cucumbers. Addition of PS to pea starch and guar gum, edible coatings improved the antifungal activity of PS against isolated spoilage molds on apples, cucumbers, and tomatoes. PS inhibition was most effective against C. herbarum on apples and least effective against P. oxalicum on cucumbers.

Stability of cardamom (Elettaria cardamomum) essential oil in microcapsules made of whey protein isolate, guar gum, and carrageenan.

UNLABELLED The effects of microencapsulating cardamom essential oil (CEO) in whey protein isolate (WPI) alone and combined with guar gum (GG) and carrageen (CG) on microencapsulation efficiency, oil chemical stability, and microcapsule structure were investigated. Freeze-dried microcapsules were prepared from emulsions containing (w/w): 15% and 30% WPI; 0.1% GG, and 0.2% CG as wall materials with CEO (at 10% of polymer concentration) as core material, and physical properties and chemical stability were compared. Bulk density of microcapsules was highest in WPI without GG or CG and in 30% WPI + GG microcapsules, and was more affected by moisture content (r = -0.6) than by mean particle diameter (d43 ; r = -0.2) and span (r = 0.1). Microcapsules containing only WPI had the highest entrapped oil (7.5%) and microencapsulation efficiency (98.5%). The concentrations of 1,8-cineole and d-limonene were used as indicators for microcapsule chemical stability since they were the main components of CEO. Microcapsules retained higher (P ≤ 0.05) concentrations of both components than non-microencapsulated CEO during 16 wk storage at 20 ºC, but higher loss of both components was noted at 35 ºC. Microencapsulated d-limonene was reduced faster than 1,8-cineole regardless of temperature. The 30% WPI and 30% WPI + GG microcapsules retained CEO best throughout storage at both storage temperatures. Scanning electron micrographs revealed that WPI microcapsules had smooth surfaces, were relatively homogenous and regular in shape, whereas GG and CG addition increased visual surface porosity and reduced shape regularity. It was concluded that the best formulation for encapsulating CEO was 30% WPI. PRACTICAL APPLICATION Encapsulating cardamom essential oil in whey protein isolate alone or combined with guar gum produced dried powders that effectively retained and chemically stabilized CEO, and therefore enhanced its handling and storability.

Predicting farinograph parameters by rapid visco analyser pasting profile using partial least square regression

Farinograph parameters are widely used to predict flour and dough functionality. Accurate prediction of farinograph parameters using other instruments would provide key information in determining cereal products quality and functional properties. This study was undertaken to provide calibration models using rapid visco analyser (RVA) to predict farinograph flour parameters and dough end-use functionality. A total of 267 samples consisted of wheat flour substituted with various ratios of disrupted chickpea (Cicer arietinum) and lentil (Lens culinaris) flours were used in this study. Samples (n=237) were randomly selected and used to develop calibration models of farinograph parameters using RVA profile. Another sample set consisting of 30 flour samples were used to validate the developed models. The partial least squares regression method using the RVA profile was used to develop prediction models for farinograph parameters treatments. Farinograph parameters (water absorption, peak time, mixing tolerance i...

Effect of microencapsulation of cardamom’s essential oil in gum Arabic and whey protein isolate using spray drying on its stability during storage

Cardamom essential oil (CEO) was microencapsulated in different materials; gum Arabic (GA), whey protein isolate (WPI) or their combinations (WPI+GA) at different mixing proportions; 1:1 and 3:1, respectively by using spray drying procedure. The stability of the encapsulated oil was evaluated by determining the concentration of encapsulated oil during storage at two temperatures (7 and 25 °C). Results showed that regardless of the storage temperature, GA microcapsules had the highest microencapsulation efficiency and retention of CEO throughout the storage period. However WPI microcapsules had the lowest microencapsulation efficiency and retention of CEO. Both WPI+GA combinations showed intermediate microencapsulation efficiency and CEO retention compared to the single component matrices. Micrographs revealed that both WPI and GA microcapsules were spherical in shape. However, WPI microcapsules had broken surfaces, whereas the GA microcapsules had dented and wrinkled surfaces. In conclusion, GA microcapsu...

Resistance to moist conditions of whey protein isolate and pea starch biodegradable films and low density polyethylene nondegradable films: a comparative study

Biodegradable packaging materials are degraded under the natural environmental conditions. Therefore using them could alleviate the problem of plastics accumulation in nature. For effective replacement of plastics, with biodegradable materials, biodegradable packages should keep their properties under the high relative humidity (RH) conditions. Therefore the objectives of the study were to develop biodegradable packaging material based on whey protein isolate (WPI) and pea starch (PS). To study their mechanical, oxygen barrier and solubility properties under different RHs compared with those of low density polyethylene (LDPE), the most used plastic in packaging. Films of WPI and PS were prepared separately and conditioned at different RH (30-90%) then their properties were studied. At low RHs ( 40% RH. Oxygen permeability of WPI and LDPE did not adversely affected by increasing RH to 65%. Furthermore, WPI and LDPE films had lower degree of hydration at 50% and 90% RH and total soluble matter than PS films. These results suggest that WPI could be successfully replacing LDPE in packaging of moist products.

Sequential Acid, Alkaline, and Enzymatic Modifications of Chickpea and Lentil Flours Impacted Batter Physical Properties

The effect of sequential acid, alkaline, and enzymatic treatment of chickpea and lentil flours on batter rheological properties was investigated. Substitution of wheat with disrupted chickpea and lentil flours significantly (P < 0.05) increased water-holding capacity from 66.8% in wheat flour to more than 70.0% based on the disruption treatment, indicating an improved adhesion of coated batter. Flow behavior index of batter treatments of partially replaced wheat flour with various ratios of disrupted chickpea and lentil flours ranged from 0.88 to 1.36 and was significantly (P < 0.05) lower than the flour (i.e., 2.15) and nondisrupted control (i.e., 1.28–1.38 for chickpea and 1.22–1.28 for lentil) flours. Consistency coefficients of disrupted chickpea and lentil flours were significantly (P < 0.05) greater when replacing wheat control, indicating a best fit for the shear-thickening model. Flour disruption decreased the treatment’s pasting properties, except the setback, providing support for the significan...