Improved Radical Scavenging Activity of .BETA.-Lactoglobulin-xylobiose Modified by the Maillard Reaction

Abstract

Milk, especially bovine milk, is widely consumed, and is processed into various foods such as cheese and butter. Whey, the main residue of dairy industries, contains appreciable amounts of proteins such as β lactoglobulin (β LG), α lactoalbumin and immunoglobulin. 1)Although many approaches to utilize the whey proteins have been tried, the uses of the proteins are limited. From a technological perspective, one of the most frequently encountered problems with milk is the non enzymatic browning that results from the Maillard reaction, especially at high temperatures during thermal treatments. The reaction occurs between milk proteins and lactose, the most abundant milk sugar. In this reaction, reducing sugars react with an amino acid to produce a Schiff base and an Amadori compound in the first steps, and then advanced glycated end products (AGEs), including melanoidins, in the end stages.It has been revealed that change the nutritive and physical functions of protein were improved by the Maillard reaction, and many studies have examined this process. For example, it was reported that protein modifications improved emulsion stability, 2 5) changed the denaturation temperature of protein, 6) had positive effects on the immune system, 7 9) affected calcium transport in Caco 2 cells, 10,11) and changed functional properties of carp myosin.12) The antioxidant activity of protein also could be improved by the Maillard reaction. 13,14) On the other hand, functional oligosaccharides used as modifiers have not been extensively studied. In fact, no studies have been done using xylobiose as a modifier in the Maillard reaction. Xylo oligosaccharide positively influences enterobacterial flora, and is preferentially utilized by B. adolescentis, B. infantis and B. longum as an energy source. 15) In our preliminary study, it was found that xylobiose could react with protein faster than maltose and lactose. This study was done ( i ) to develop a new food resource using whey proteins, especially β LG, (ii) to improve whey protein function via the Maillard reaction, and (iii) to investigate radical scavenging activity of β LG xylobiose. MATERIALS AND METHODSMaterials. β lactoglobulin (β LG) from bovine milk was purchased from Sigma (St. Louis, MO, USA). Xylobiose was purchased from Towa Chemical Industry Co., Ltd. (Tokyo, Japan). Lactose was purchased from Nacalai Tesque (Kyoto, Japan).Preparation of β-LG-xylobiose conjugate. β LG and saccharides were dissolved in 0.2 M phosphate buffer (pH 7.8), and the final concentration of β LG and the saccharide were adjusted to 5 mg/mL. The solution was frozen at 40 C and lyophilized in a freeze dryer (FD 81, Tokyo Rika Kikai Co., Ltd., Tokyo, Japan) for 4 days to obtain a powder. The lyophilized powders were incubated at 40 C and 30 40% relative humidity in the incubator (MIR 152, Sanyo Electric Co., Ltd., Osaka, Japan), and were kept under these conditions for 1, 4 and 7 days. To remove unreacted saccharides, conjugated β LG xylobiose was dissolved in distilled water and dialyzed for 3 days...

Changes in partial properties of glycosylated egg white powder during storage

“…The possible reason may be the high reductive saccharide content and the high Maillard reaction activity of XOS. [14][15][16] Additionally, the free amino groups of native EWP had almost no changes during storage (the data was not given).…”

“…10 Additionally, XOS, a kind of pentose and oligosaccharide, has higher Maillard reaction activity than commonly used polysaccharides and is suitably used as a donor saccharide for EWP glycosylation. [14][15][16] However, the current research on modified EWP was primarily concerned with improving their physicochemical and functional properties after glycosylation with various carbohydrates. There was a lack of research into the property changes of modified EWP during storage.…”

“…It can promote the proliferation activity of intestinal Bifidobacterium and can be used as functional components 10 . Additionally, XOS, a kind of pentose and oligosaccharide, has higher Maillard reaction activity than commonly used polysaccharides and is suitably used as a donor saccharide for EWP glycosylation 14‐16 …”

Effect of water activity, temperature and pH on solid state lactosylation of β-lactoglobulin

“…On one hand, lactosylation alters the composition and properties of the whey proteins, and should therefore be minimized during whey protein preparation. On the other hand, attachment of lactose or other carbohydrates to dairy proteins has been shown to confer antioxidant properties to the protein (Chobert, Gaudin, Dalgalarrondo, & Haertlé, 2006;Lee, Tseng, & Wu, 2001;Yajima, Onodera, Takeda, Kato, & Shiomi, 2007), and to improve their functional properties (Chevalier, Chobert, Popineau, Nicolas, & Haertlé, 2001;Medranoa, Abiracheda, Panizzoloa, Moynaa, & Añónb, 2009;Nacka, Chobert, Burova, Léonil, & Haertlé, 1998;Oliver, Melton, & Stanley, 2006). In both instances, it is important to be able to control the extent of lactosylation to tailor and manipulate the properties of the proteins.…”