Foods are very important to human body. According to Vittadini et al. (2001), foods provide energy that isneeded for human in order to do daily activities. Besides that, food is important for growth and it supplies vitamins and minerals to repair any damage in human skin and also prevent the body to get illnesses easily (Vittadini et al., 2001). Human body cannot use food that they eat directly until it is broken down into small molecules(Campbell et al., 2008). Therefore, the food needs to be process first. Food processing in human body systems consists of ingestion, digestion, absorption and elimination (see figure 1).
The first stage of food processing is the ingestion, the act of eatingfollowed by digestion processes(Campbell et al., 2008).The process of food broken down into simple molecules that been absorbed by the human body is called digestion.Digestion is split into two different processes which are physical digestion (grounding of large molecules of food into smaller particles) and chemical digestion (enzymes released into the digestive tract use to break down large polymeric biomolecules into monomers or oligomers (dimers or trimers). Both ingestion and digestion occurs in the mouth or oral cavity(Campbell et al., 2008).
Physical digestion begins in the oral cavity. There are three major parts of the oral cavity: teeth, tongue and salivary glands. Hoebler et al. (1998) stated that the food was break down into smaller pieces by using teeth, tongue and saliva. In the mouth, teeth act as a tool that mechanically reduced size of food into small pieces. However, the tongue manipulates food bolus by pushing it for swallowing (Hoebler et al.,1998). The last part of the oral cavity is salivary glands. In the salivary glands, it secretes saliva. Furthermore, enzyme that contain in the saliva is salivary amylase (common form of starch). This enzyme helps to break down amylase into maltose(Campbell et al., 2008).
After finished processing food at the oral cavity, the small molecule of food is pushing down to the pharynx or throat region. The function of the pharynx is as a respiratory passage. According to Campbell et al. (2008), pharynx is open to two passage ways that areesophagus and trachea. The esophagus is connected to the stomach while trachea connected to the lungs. The swallowing of food occurs at trachea and it must be carefully choreographed to keep food from entering and blocking the airway. When human swallow the food, an epiglottis (flap of cartilage) being covered by glottisprevents food from entering the trachea. This swallowing mechanism directs each bolus (rounded mass of chewing food for swallowing) into the entrance of the esophagus. Esophagus consists of striated and smooth muscle. The striated muscle is located at the upper part of esophagus and is functioning during swallowing while the smooth muscle is important for peristalsis, the waves of circular muscle contraction. It is also known as the rhythmic cycles of contraction move each bolus to the stomach (Campbell et al., 2008). Carbohydrates are a versatile class of molecules consisting of carbon (C), oxygen (O) and hydrogen (H) in the ratio of every one carbon atom backbone attached with two hydrogen atom and one oxygen atom (Insel, Ross, McMahon &Bernstein, 2012; Fink, Burgoon&Mikesky, 2011). Carbohydrates are classified into two types, simple carbohydrate (sugars) and complex carbohydrate (starch and fibre) (Insel et al., 2012). Chemical digestion of carbohydrate begins in the mouth when enzyme salivary amylase (or ptyalin) is secreted from the serous cells of the salivary gland which are the parotid gland, submandibular glands, andbuccal glands, that are located near the mouth. Polysaccharide amylose (starch) broken down into the disaccharide maltose by the salivary amylase. The broken down food will be swallowed and passed to the stomach through the esophagus. However, chemical...