The purpose of this study focuses on modifying β-LG (β-lactoglobulin)in buttermilk via supercritical CO_2 treatment, to reduce its antigenicity.In dairy industry, supercritical fluid extraction (SFE) is applied primarilyin fat extraction. Yet it is possible to utilize SFE as a reactor in foods.Milk is an essential energy source for infants. However, formula is stillneeded in some instances and there are some children allergic to dairybased products. In milk proteins, β-LG is believed to be a prevalent allergenin cow’s milk. Buttermilk powder was used because of its abundantmilk fat globule membrane and phospholipids content. It was treated inSFE system with food grade CO_2 at 100, 150, 200, 250, 350, 400 bars,with 50 and 75°C in each condition. All analyses were completed in 10%buttermilk suspension (wt/vol). Buttermilk proteins were examined inSDS-PAGE, Western-blot, and ELISA. Orbitrap Fusion HPLC-MS/MSand periodic staining were used to check any post-translational modification.Purified β-LG was used to evaluate the cytotoxicity, viability, andinflammatory response in Caco-2 cell line by the mean of LDH, MTT,and IL-8, respectively. The SDS-PAGE quantification showed that thesignal intensity of β-LG bands was reduced in a maximum of 45.8%after being processed under 250 bar/75°C, 30 min. Lighter and diffusedsignals were also found in Western-blot. ELISA tests proved that ourtreatment can significantly change the β-LG antigenicity in buttermilk(P < 0.05). Around 146-Da molecular weight increment was detected ontreated β-LG by Orbitrap Fusion. Sugar moieties in glycoproteins wererevealed by periodic staining. Treated β-LG showed 95% viability and27% lower inflammation without any cytotoxicity in Caco-2 cells, comparedwith untreated β-LG. These results showed that β-LG reductionwas completed by glycosylation, which has been reported as a possiblepathway to reduce the allergenicity in foods. The denaturation of β-LGin supercritical fluid processing is a promising way to solve milk allergy,which is still a problem requiring more attention and further research.
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