Plasma Modified Membrane for Daily Recovery of Oil from Repeated Frying Operation with Frequent Oil Replenishment

Sunflower oil was used for deep frying of potatoes at 170 +/- A 5 A degrees C and for 8 h per day for 5 days in a fryer with an automatic oil filtration system. Three different frying operations were performed: operation (OP)-1, OP-2 and OP-3; that correspond to the oil unfiltered at the end of each frying day, the oil filtered through the fryer's own filter (passive filtration) and the oil firstly subjected to passive filtration and then filtered through a polyethersulfone membrane modified with hexamethyldisiloxane via radio frequency plasma (75 W-5 min, discharge power-time), respectively. The performance of each operation was investigated in terms of free fatty acids (FFA), conjugated dienoic acids (CD), TOTOX value, total polar content (TPC), Hunter color, viscosity, fatty acid composition, and tocopherol content. The results showed that OP-3 could decrease FFA, CD, TOTOX, TPC, L*a*b* value, viscosity and linoleic acid (18:2)/palmitic acid (16:0) ratio in 29.6, 11.7, 25, 30.8, 6.1*11.3*20.8*, 7.8, 12.2 %, respectively, compared to the unfiltered oil (OP-1). Regenerated oil from OP-3 had a frying life approximately 17 h more than oils from both OP-1 and OP-2

Quality changes of hazelnut kernels subjected to different cold plasmas and gamma irradiation treatments

In this study, physicochemical parameters of hazelnuts after atmospheric-pressure (AP:air, 3000 L/h, 655 W, 25 kHz, 1.7 min) and low-pressure (LP:air, 25 Pa, 100 W, 13.56 MHz, 30 min) cold plasmas, and gamma irradiation (GMI:10 kGy, 10 min) treatments, and untreated and treated hazelnuts after accelerated storage for 30 days(60 °C) were investigated. All treatments significantly reduced moisture (26–47%), aw (16–48%), oil (13–15%), soluble phenolic content (SPC; 26–36%) and total tocopherols (TT; 8–38%) compared to untreated hazelnut (Control-1) while no significant changes determined between treatments and Control-1 in terms of L*a*b*, protein, total sugars (TS) and total phenolic compounds. However, TS of all treatments after storage were significantly increased (3.2–33%) while aw (7–27%) and TT (13–31%) of all treatments were significantly decreased compared to both Control-2 and before storage (p < 0.05). Among treatments, cold plasmas showed great potential for conservation of most tested parameters

Detoxification of hazelnuts by different cold plasmas and gamma irradiation treatments

The detoxification effects of cold atmospheric-pressure (AP,3000 L/h of air, 25 kHz, 655 W-1.7 min)and low-pressure (LP,air-100 W-30 min)plasmas and gamma irradiation(GMI,10 kGy-10 min)treatments on different concentrations of pure aflatoxin B1(AFB1)and AFB1 + B2 (TotAFs)as well as same toxins spiked on hazelnut were investigated. Both plasmas reduced 72–73% of AFB1 (3 ppb)spiked on hazelnuts while GMI reduced 47% of AFB1. TotAFs (6 ppb)reductions on hazelnut after both plasmas were 70–71%, which was also higher than that of GMI (15.5%). However, the reductions in pure AFB1 at 1–50 ppb and TotAFs at 1.03–51.5 ppb after GMI (97–100%)were higher than those of AP (55–75%)and LP (69–90%)plasmas. AP plasma has the potential to be an alternative to conventional detoxification methods because it is both effective on aflatoxins in foods and maintains the sensory attributes of food evaluated by a sensory panel. Industry relevance: The use of plasma technology in foods for detoxification purposes is an economic alternative to conventional and other non-thermal processes as well as meeting the industry's demand for sustainable development. This study showed that different cold plasmas are capable of reducing the aflatoxins as pure forms as well as in food. The results contributed to the understanding of cold plasma detoxification effects on aflatoxins and could be a basis for a possible industrial implementation

Aspergillus decontamination in hazelnuts: Evaluation of atmospheric and low-pressure plasma technology

The decontamination effects of non-thermal atmospheric-pressure (AP)and low-pressure (LP)plasma systems were investigated on hazelnuts artificially contaminated with Aspergillus parasiticus and Aspergillus flavus spores. Furthermore, AP-plasma treatment conditions were also optimized. Spore reductions of 5.6 and 4.7 log cfu/g in Aspergillus parasiticus and Aspergillus flavus, respectively, were achieved after 100 W-30 min of LP-air-plasma treatment. Similarly, 5.5 and 5.4 log cfu/g of reductions in Aspergillus parasiticus and Aspergillus flavus, respectively, were achieved after AP-air-plasma treatment at 3000 L/h of gas flow rate, frequency of 25 kHz and reference voltage of 100% (655 W)for 5-cycles (1.7 min). Deformation of spores and loss of spore integrity after plasma treatments were demonstrated with scanning electron microscope (SEM). This study showed that LP and AP plasma treatments might be an alternative method for inactivation of aflatoxin- producing fungi. Industrial relevance: Non-thermal (cold)plasma is a promising technology for decontamination of foods due to its safety, ease of use and low temperature processing capability. The results of this study showed that plasma system can be incorporated into a food processing chain, and when initial Aspergillus spp. spores were 7.8–7.9 cfu/g in hazelnut, plasma treatment with reductions of up to 5.6 log cfu/g can compete with other decontamination methods

Effects of linalyl oleate on soybean oil flavor and quality in a frying application

Bread pieces were fried at 180 degrees C in soybean oil (SBO) containing no additives (control), 0.1% linalyl oleate (LO), or 10 ppm methyl silicone (MS). After 2 h of heating, the MS-containing oil was the most stable, followed by the oil with LO and the control, based on conjugated dienoic acid percentage (CD) and the ratio of linoleate%/palmitate%. Oil extracted from the fresh fried bread showed similar, but not significant, trends for CD and PV. Fresh and stored (60 degrees C, 2 days) bread fried in LO-containing oil had less hexanal than the other two treatments, and the stored LO bread had less t,c- and t,t-2,4-heptadienal than the control. Fresh bread fried in LO-containing oil had a less rancid flavor than did the other two treatments, and the LO treatment had less fishy flavor than the control. In stored bread, the MS treatment was less rancid than the control. In oil extracted from the stored bread, the amounts of t,c-2,4-heptadienal and 2-decenal correlated (p <= 0.05) with the amounts of individual unsaturated fatty acids and with CD, but only t,c-2,4-heptadienal correlated with the PV. The t,c-2,4-heptadienal correlated with individual Polyunsaturated fatty acids (PUFA) in freshly fried bread. In general, oil and fried bread had improved flavor quality and/or oil stability when they contained MS or LO