Properties of Biocomposites Made of Extruded Apple Pomace and Potato Starch: Mechanical and Physicochemical Properties.

This paper presents research results on biocomposites made from a combination of extruded apple pomace (EAP) and potato starch (SP). The aim of this work was to investigate the basic properties of biocomposites obtained from extruded apple pomace reinforced with potato starch. The products were manufactured by hot pressing using a hydraulic press with a mould for producing samples. The prepared biocomposites were subjected to strength tests, surface wettability was determined, and a colour analysis was carried out. A thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and cross-sectioning observed in a scanning electron microscope (SEM) were also performed. The obtained test results showed that the combination of apple pomace (EAP) and starch (SP) enabled the production of compact biocomposite materials. At the same time, it was found that each increase in the share of starch in the mixture for producing biocomposites increased the strength parameters of the obtained materials. With the highest share of starch in the mixture, 40%, and a raw material moisture content of 14%, the material had the best strength parameters and was even characterised by hydrophobic properties. It was also found that materials with a high content of starch are characterised by increased temperature resistance. The analysis of SEM microscopic photos showed well-glued particles of apple pomace, pectin, and gelatinised starch and a smooth external structure of the samples. Research and analyses have shown that apple pomace reinforced only with the addition of starch can be a promising raw material for the production of simple, biodegradable biocomposite materials.

Micronized Powder of Raspberry Pomace as a Source of Bioactive Compounds.

Red raspberries, which contain a variety of nutrients and phytochemicals that are beneficial for human health, can be utilized as a raw material in the creation of several supplements. This research suggests micronized powder of raspberry pomace production. The molecular characteristics (FTIR), sugar, and biological potential (phenolic compounds and antioxidant activity) of micronized raspberry powders were investigated. FTIR spectroscopy results revealed spectral changes in the ranges with maxima at ~1720, 1635, and 1326, as well as intensity changes in practically the entire spectral range analyzed. The discrepancies clearly indicate that the micronization of the raspberry byproduct samples cleaved the intramolecular hydrogen bonds in the polysaccharides present in the samples, thus increasing the respective content of simple saccharides. In comparison to the control powders, more glucose and fructose were recovered from the micronized samples of the raspberry powders. The study's micronized powders were found to contain nine different types of phenolic compounds, including rutin, elagic acid derivatives, cyanidin-3-sophoroside, cyanidin-3-(2-glucosylrutinoside), cyanidin-3-rutinoside, pelargonidin-3-rutinoside, and elagic acid derivatives. Significantly higher concentrations of ellagic acid and ellagic acid derivatives and rutin were found in the micronized samples than in the control sample. The antioxidant potential assessed by ABTS and FRAP significantly increased following the micronization procedure.

Response Surface Methodology Approach for Predicting Convective/Infrared Drying, Quality, Bioactive and Vitamin C Characteristics of Pumpkin Slices.

In this research, a convective/infrared (CV/IR) dryer was used to dry pumpkin slices. For optimization of the drying conditions, the influence of three levels of independent variables including air temperature (40, 55, and 70 °C), air velocity (0.5, 1, and 1.5 m/s), and IR power (250, 500, and 750 W) were assessed by response surface method (RSM) through a face-centered central composite design. Analysis of variance (non-fitting factor and R2 value) was employed to determine the desirability of the model. Response surfaces and diagrams were also utilized to show the interactive influence of the independent variables with the response variables (drying time, energy consumption, shrinkage, total color variation, rehydration ratio, total phenol, antioxidant, and vitamin C contents). According to the results, optimal drying conditions involved a temperature of 70 °C, air velocity of 0.69 m/s, and IR power of 750 W. At the mentioned conditions, response variables of drying time, energy consumption, shrinkage, color, rehydration ratio, total phenol, antioxidant, and vitamin C contents were 72.53 min, 24.52 MJ/kg, 23%, 14.74, 4.97, 617.97 mg GA/100 g dw, 81.57%, and 4.02 mg/g dw, with a confidence level of 0.948, respectively.

Interaction of Different Drying Methods and Storage on Appearance, Surface Structure, Energy, and Quality of Berberis vulgaris var. asperma.

Seedless barberry fruit is native small fruit in Iran. To examine the impact of various drying methods and storage on the biochemical attributes (Vitamin C, Anthocyanin, Phenol, pH, TA), color index (a*, b*, L*, ab, and Chroma), drying time, and fruit microstructure (by SEM) of seedless barberry (Berberis vulgaris var. asperma), and effective moisture diffusivity coefficient (Deff), specific energy consumption (SEC), energy efficiency (EE) of the dryers, this experiment was performed. Drying treatments include microwave (100, 170, and 270 W), oven (60 and 70 °C), cabinet (50 and 70 °C), shade, sun, and fresh samples (control) and storage 6 months after drying (in polyethylene packaging and at a temperature of 5-10 °C). Results showed minimum and maximum drying times (50 min and 696 h), were related to microwave (270 W) and shade methods, respectively. The highest color values were observed in fruits treated with control, shade and sun treatments and the lowest values were observed in cabinet (70 °C) methods. According to the SEM results, microwave significantly affected surface structure of the dried sample compared to others. The findings indicated that the use of artificial drying methods than natural methods (sun and shade) cause a more significant reduction in color indexes, while vitamin C, soluble solids, and anthocyanin were significantly maintained at a high level. Storage reduced anthocyanin content of fruits almost 12%. Moreover, it was discovered EE and SEC values varied in the range of 1.16-25.26% and 12.20-1182 MJ/kg, respectively. Deff values were higher in microwave 270 W.

Examination of the Peleg and Normand equation during relaxation of wheat: The effect of holding time.

In this study, we analyzed the effect of the duration of relaxation experiments on the parameters of the model proposed by Peleg and Normand. The relaxation experiments were conducted for individual intact wheat kernels in compression. Single kernels were initially loaded with a force of 20 N, then maintained at a constant deformation over time of 300 s. For the following time intervals 0-10, 0-20, 0-30, 0-40, 0-50, 0-60, 0-120, 0-180, 0-240, and 0-300 s coefficients k1 , k2 and Y(t) were determined according to the Normand and Peleg equation. The effect of time was compared at variable wheat moisture ranging from 8 to 20%. For longer holding times, the relaxed force was higher and the decay parameter, Y(t), decreased. The coefficient k1 increased proportionally with increase in the time of relaxation from ~3.3 to 23.3 s. The values of coefficient k2 declined for longer experiments, and the decline was relatively quick for up to 60 s and then asymptotically diminished. The effect of time on the decay parameter Y(t) and coefficients k1 and k2 depended on the moisture of kernels. The accuracy of the models was significantly different for the studied holding times. The highest standard error of the estimate was evidenced for 10 s experiments, and its minimum was noted at times close to 120-180 s.