Stable Mixed Beverage is Produced from Walnut Milk and Raw Soymilk by Homogenization with Subsequent Heating

Abstract

Walnut milk, which is generally produced in the presence of stabilizers by homogenization, is being increasingly consumed by people in China, due to its good nutritional and functional properties. In this study, the mechanism behind the poor dispersion stability of walnut milk without stabilizer has been clarified as caused by heat-induced large aggregate formation from walnut oil bodies and protein. It was found that addition of raw soymilk into walnut milk could result in the stable mixed beverage by homogenization with subsequent heating. This was because raw soymilk played roles on decreasing the particle size of walnut oil bodies during the homogenization, and preventing the large aggregate formation from walnut oil bodies and protein during the subsequent heat treatment. Amino acid analysis showed that the stable mixed beverage contained more lysine than the walnut milk. In addition, the stable mixed beverage had higher levels of protein content (about 2%) than the commercial walnut milk (commonly < 1%) in China. Therefore, this study was meaningful for the convenient and value-added utilization of walnut.Keywords: walnut milk, soymilk, mixed beverage, walnut oil bodies, walnut protein IntroductionWalnut is one of the mostly cultivated tree nuts in the world, including southern Europe, northern Africa, eastern Asia, the USA and western South America (Martinez et al., 2010), and China is the leading producer. It is consumed due to its nutritional, healthy and sensory attributes. It has been reported that walnut exhibits greater antioxidant capacity than any other nuts (Arranz et al., 2008) and its oil has a perfect balance of n-6 and n-3 polyunsaturated fatty acids (4:1) (Simopoulos, 2002). The consumption of walnut can lower plasma total-and low-density lipoprotein cholesterols (Lavedrine et al., 1999;Banel and Hu, 2009), and incidences of cardiovascular diseases (Simopoulos, 2002). In addition, the intake of walnut has been proved to effectively reduce inflammation and improve arterial functions (Ros et al., 2004;Tapsell et al., 2004).The most popular walnut products are made from toasted nuts.However, not many people may be motivated to consume the toasted walnut all the times due to the inconvenience of the shell removal. Therefore, the walnut products, convenient to the consumers, are prioritized by the food industry. Some food scientists have tried to produce walnut-containing meat products (Cofrades et al., 2004;Ayo et al., 2005). Nevertheless, the most popular way is the production of walnut milk beverage (Gharibzahedi et al., 2012;Luo et al., 2010;Yu et al., 2010). But poor dispersion stability of walnut milk is a key limiting factor.Until now, the mechanism behind the poor dispersion stability is unclear. Commonly, homogenization in the presence of various stabilizers (xanthan, sodium carboxymethyle cellulose, monoglyceride, sucrose ester, sodium caseinate, arabian gum and so on) is a well-used strategy to produce stable walnut milk beverage (Gharibzahedi et al., 2012;Luo et al., 2010;Yu et al., 2...

Effect of multi-pass high pressure homogenization on physicochemical properties of hazelnut milk from hazelnut cake: An investigation by response surface methodology

“…As expected, a progressive disintegration of particles was observed because of high pressure shredded the suspended particles during homogenization, resulting small particles such as cellular material, fiber fractions, and polymers (Yu et al, ). These findings were also in accordance with the results obtained by Bernat et al () for almond and hazelnut milk, by Chen et al () for walnut milk and walnut milk and soymilk mixture, and by Cruz et al () for soy milk. However, as seen in Figure b, the increase in the tendency of the small particles to agglomerate during homogenization at high pressure is due to the increase in the surface area of the suspended particles (Augusto et al, ; Kubo et al, ).…”

“…As a result of flocculation and aggregation in the samples during heat treatments, larger particles were formed as compared to the unheated one, clearly indicating that heat treatment could cause the interaction between oil and protein bodies. These results are also similar to those reported for almond and hazelnut milks (Bernat et al, ) and for walnut milk (Chen et al, ).…”

“…HPH has a wide usage area especially includes food, cosmetic and pharmaceutical industries. In the literature, there are some studies related with usage of HPH such as dairy products (milk, cheese, whey protein isolates), vegetable milks (soya milk, almond milk, hazelnut milk, walnut milk), and fruit juice varieties (apple, banana, cranberry, tomato juices) (Baier, Purschke, Schmitt, Rawel, & Knorr, ; Bernat et al, ; Calligaris et al, ; Chen, Lu, Yu, Kong, & Hua, ; Devi, Buckow, Singh, Hemar, & Kasapis, ; Dhakal et al, ; Kubo, Augusto, & Cristianini, ; Suarez‐Jacobo et al, ).…”

Characterisation of yoghurt enriched with polyunsaturated fatty acids by using walnut slurry

“…Walnut milk beverage has been developed (Chen et al . ). Walnut slurry obtained from wet grinding may be used as an ingredient to develop dairy products enriched with PUFAs.…”

“…Walnuts are mostly consumed as snacks and are used in food formulations as an ingredient. Walnut milk beverage has been developed (Chen et al 2014). Walnut slurry obtained from wet grinding may be used as an ingredient to develop dairy products enriched with PUFAs.…”