###### Abstract  
In Japan, rising demand for waxy barley has led to concerns over bran waste. We investigated the effects of replacing wheat flour with different proportions of the waxy variety 'Kirarimochi' barley bran on the physical properties and health functionality of the bread. We used both the inner bran layer (IBLP) and outer bran layer (OBLP) of waxy barley as replacement sources and tested their effects on the appearance, height, specific volume, \(\beta\)-glucan, antioxidant properties, physical and sensory properties of bread. Bread with a 10% IBLP replacement group showed significantly increased height, specific volume, and softness compared to the control, indicating that IBLP at this level serves as an effective enhancer of bread volume and texture. At higher replacement levels (30-50% IBLP), the breads exhibited increased \(\beta\)-glucan content and enhanced antioxidant properties. Sensory evaluation revealed a stronger aroma, increased moistness, and stickiness of bread with 50% IBLP substitutions. OBLP was not suitable for sensory evaluation. These results show that IBLP can improve the specific volume and texture of bread and enhance its health functional components by adjusting the ratio. It also provides a clue to solving the problem of bran disposal.  
waxy barley; \(\beta\)-glucan; underutilized materials; physical properties; antioxidant properties; sensory evaluation +
Footnote †: journal: Applied sciences  
also showed that bran contains approximately 3.9-4.8 g/100 g dry weight (DW) \(\beta\)-glucan, which is lower than that in the PWB (63-79% of PWB). Nevertheless, despite its low \(\beta\)-glucan content, \"kirarimochi\" bran still represents a promising source of this valuable dietary fiber, making \"kirarimochi\" bran a beneficial health food material [9].  
Previous studies have reported the utilization of barley whole grain flour in various food applications, including fresh and dried white salted and fresh yellow alkaline noodles [10], biscuits [11], and bread [12]. In noodle products, the addition of barley flour has been shown to reduce the cooking time and improve the texture of noodles [10], while in biscuits, it increased the spread ratio [11], and in bread, it decreased the volume and increased dietary fiber and \(\beta\)-glucan content [12]. Studies on waxy barley flour have shown that replacing a portion of wheat flour in bread dough with waxy barley flour led to reduced bread volume and darker coloration; in addition, the substitution also led to firmer texture, which tended to increase with the increase in replacement ratio [13; 14]. As discussed above, there have been several reports on the health functionality and cooking and processing properties of waxy barley as whole barley flour. However, only a few studies have reported on the health functionality and cooking and processing properties of different layers of waxy barley bran [12; 15]. In Japan, waxy barley was increasingly consumed as rice grain barley and bran was produced during bounding. Investigating the cooking and processing properties of different bran parts would be a useful study to contribute to reducing the amount of glutinous barley bran waste.  
Bread is a globally consumed food that provides essential dietary fiber and minerals [16]. In recent years, research has been conducted to improve the nutritional profile of wheat flour-based bread by utilizing different sources of wheat flour rich in minerals, vitamins, proteins, and dietary fiber [17]. Based on these studies and considering the physical and health-promoting properties of 'kirarimochi', we hypothesize that incorporating 'kirarimochi' bran into bread can enhance the nutritional profile of bread by increasing \(\beta\)-glucan and antioxidant properties, while also improving its physical characteristics. To test this hypothesis, we aimed to investigate the effects of waxy barley bran addition on the appearance, color tone, height, specific volume, \(\beta\)-glucan content, antioxidant activity, and physical and sensory characteristics of bread.