The food industry faces the threat of producing and designing foods that improve human health. That also raises scientific interest concerning food components with appropriate nutritional, technological, and functional properties, which will enhance the value of food [1]. In recent years, carob has gained much attention mainly due to its appearance as a functional food. In addition, compositional, nutritional, and industrial value makes it an economically important crop [2, 3].
Carob (Ceratonia siliqua L.) is a typical Mediterranean tree species introduced to the temperate regions of Central America, Australia, and Africa [4]. Carob pods have a nutritional value of a high level of carbohydrate (67.48%), appreciable amounts of protein (6.64%) and low level of fat (2.24%), and dietary fibers (~ 11%). Also, carob is a rich source of minerals (Mg, Fe, P, Zn, Ca, K, Na) and significant amounts of phenolic compounds (gallic acid, tannins) and vitamins (D, E, C, B6, folic acid)[5, 6].
The carob fruit, also called carob pod, generally consists of the pulp/ endosperm
(80–90%) and the germ/ seed (10–20% ) by weight, each one of which is used in
a great variety of bakery products and as food additives and dietetic products [4, 7].
Carob powder can be produced from carob fruits after discharge of the seeds, followed by roasting at 120 and 180°C (typically, 150°C) for 10–60 min to obtain several degrees of roasting (low, medium, and high roast) [6, 8]. The roasted carob powder is sweeter, has a dense caramel-like taste, and has an extra cacao-like aroma at low-roasting temperatures. However, it has a more astringent taste, coffee-like flavor, and roasted aroma at a high roasting temperature. Besides, its low glycemic index food and low glycemic load make it a cocoa alternative and natural sweetener in bakery products, particularly cocoa-containing cake recipes and dietetic food [6, 8–11].
The production of gluten-free baked products is challenging because, due to the lack of gluten, the dough cannot sufficiently retain air during mixing and carbon dioxide from yeast during proofing, resulting in a less cohesive structure [12]. Therefore, improvement of the quality of gluten-free bread requires the addition of ingredients that present similar properties to gluten. Many researchers have attempted to use proteins, hydrocolloids, emulsifiers, enzymes, or a combination of the above [13]. For that, carob seeds are used to produce Locust Bean Gum (LBG), which could be used as a thickener, hydrocolloid, stabilizer, emulsifier, and gelling agent in the food industry, and is approved in most areas of the world; chemically known as E410 to mimic the viscoelastic properties of gluten to improve dough handling and to improve the overall quality of finished baked products. LBG is characterized by biodegradability, low toxicity, and low cost contributing to its significant utilization in various products [4, 14].
Accordingly, the present research work aimed to (i) utilize the roasted carob powder from the pulp (130° C/ 30 min) as a natural sweetener in replacement with cane sugar at 0, 25, 50, and 75% in cacao cupcakes formula; (ii) utilize carob bean gum from seeds as a by-product of pods in gluten-free bread at 0, 0.5, 1.0 and 1.5%, (iii) assess the chemical, viscosity and antioxidant properties of the raw materials, (iv) evaluate the sensory, physicochemical and texture properties of the produced cupcakes and gluten-free bread.