Determining the effect of UV-C, high intensity ultrasound and nonthermal atmospheric plasma treatments on reducing the allergenicity of α-casein and whey proteins

Abstract

Determining the effect of UV-C, high intensity ultrasound and nonthermal atmospheric plasma treatments on reducing the allergenicity of a-casein and whey proteins. Determining the effect of UV-C , high intensity ultrasound and nonthermal atmospheric plasma treatments on reducing the allergenicity of α-casein and whey proteins Abstract:Casein, β-lactoglobulin and α-lactalbumin are major milk protein allergens. The objective of this study was to investigate the effect of high intensity ultrasound, nonthermal atmospheric plasma and UV-C light treatments in reducing the allergenicity of isolated major milk proteins. SDS-PAGE results for ultrasound and plasma treatments showed no noticeable change in gel band intensities for -casein, β-lactoglobulin and α-lactalbumin, indicating no change in protein concentration. Ci-ELISA analysis showed that there was no significant difference (p > 0.05) in IgE binding values for control and treated samples in ultrasound and plasma treatment conditions tested in this study. UV-C treatment for 15 min resulted in reduced intensities of all three protein bands in SDS-PAGE gel. Ci-ELISA of UV-C treated samples showed, significant reduction (p < 0.05) in IgE binding values compared to control samples indicating reduction in allergenicity of proteins (25% reduction for -casein and 27.7% reduction for whey fractions). Further investigations using in vivo clinical trials need to be conducted to confirm this result.Key words: UV-C light, High intensity Ultrasound, Nonthermal atmospheric plasma, Milk, Allergen, IgE binding. Abbreviations: UV-C = Ultraviolet-C, SDS-PAGE = Sodium dodecyl sulfate polyacrylamide gel electrophoresis, Ci-ELISA = Competitive indirect enzyme-linked immunosorbent assay, PBS = Phosphate buffered saline, PBST = Phosphate buffered saline with Tween 20, NTAP =Nonthermal atmospheric plasma, PUV = Pulsed UV light. IntroductionMilk is one of twelve allergenic ingredients whose presence has to be declared as per the directive 2003/89/EC (Monaci et al., 2006). Milk allergy is the most common food allergy in the children under the age of two years. About 1.6 to 2.8 % of this population have cow milk allergy (Poms et al., 2004). About 85% of those children outgrow their milk allergy after the age of three years. Approximately 0.3 to 7.5% of the world population is reported to be affected by cow milk allergy (El-Agamy, 2007).Almost all proteins in milk are allergens even at low concentrations (Wal, 2004). Milk contains two types of protein, casein and whey in 80:20 ratio. α-lactalbumin and β-lactoglobulin are the major components of whey. Caseins are the most allergenic proteins in milk followed by β-lactoglobulin and α-lactalbumin (Natale et al., 2004). Milk is a very rich nutrition source and is used as an ingredient in most of the weaning foods. Hence avoiding milk may lead to malnutrition in children and may affect their growth. Several researchers attempted to reduce milk allergenicity by applying different processing treatments. Although some of the treatments reduced a...

Structural and oxidative modifications, and antioxidant activity of β-lactoglobulin treated by ultraviolet light-C and ultrasound

“…[3,10,15] As shown in Figure 1, no significant changes were observed in the electrophoretic behaviour of β-Lg after ultrasound treatment compared with the control, indicating that β-Lg was still present after exposure to ultrasound without a change in molecular weight induced by protein degradation. Similar results have been obtained in the SDS-PAGE studies of ultrasonication-treated β-Lg, [21] ovalbumin, [19] and black bean protein isolate. [27] The band intensity of β-Lg had slightly decreased after UV-C treatment, especially the 30-min UV-C treatment (Figure 1).…”

“…[12] Ultrasound treatment Ultrasound treatment was carried out using a high-intensity ultrasound liquid processor (Zealway, China) operating at 40 kHz with an input power of 900 W. A 50 mL (2 mg/mL) of protein solutions in a 100-mL beaker were placed into the ultrasonic tank and treated for 15 or 30 min. [21] Water temperature fluctuation inside the ultrasonic bath was lower than 2°C during the treatment. After treatment, all samples were stored at -20°C until analysis.…”

“…Similarly, UV-C treatment for 15 min resulted in reduced β-Lg band intensities, which reduced more with increasing treatment time. [21] A previous study also reported the removal of α-casein bands after 180 s of UV-light treatment due to the slight breakdown of polypeptide chains. [28] These differences were related to the spectral range, light intensity, sample depth, amino acid composition, and molecular structure.…”

The effects of pulsed ultraviolet light, cold atmospheric pressure plasma, and gamma-irradiation on the immunoreactivity of soy protein isolate

“…More recently, nonthermal food processing technologies have emerged in the food industry due to their negligible effects on food properties (Huang, Hsu, Yang, & Wang, 2014;Shriver & Yang, 2011). Different studies have shown that nonthermal technologies such as high pressure processing (HPP) hold a great promise for the development of food ingredients with reduced allergenicity (Tammineedi, Choudhary, Perez-Alvarado, & Watson, 2013;Yang et al, 2010).…”

Safety of UV‐treated milk as a novel food pursuant to Regulation (EC) No 258/97

“…α-casein, β-lactoglobulin and α-lactalbumin) following irradiation with UV-C (Tammineedi et al, 2013).…”