Role of Enzymes in Development of Functional Foods and Food Products
Protiva Rani Das, Kashif Ameer and Jong-Bang Eun
Most of the chemical processes take place in extreme environmental conditions, such as elevated temperature and pressures, and these harsh conditions result in massive consumption of energy and hazardous chemicals. Non-specificity also causes production of by-products which exert harmful effects on the environment (Jegannathan and Nielsen 2013). Therefore, there is a need for clean, environment- friendly, reliable and bio-compatible industrial production processes. The use of biocatalysts has risen since the last decade as clean and environment-friendly alternatives to ensure increasing demands of sustainable development and more and more researchers are focusing their interests to develop novel strategies. Biocatalysts have been divided into two categories broadly: (1) whole cellular moieties and (2) isolated enzymes. Purified enzymes are more advantageous because of the simplicity of the involved apparatus, higher yields of target compounds and consequently clean and high-quality recovery of products through eliminating need of unwanted side reactions (Kirk, Borchert, and Fuglsang 2002). Enzyme-assisted extraction
(EAE) allows to achieve these objectives with minimum adverse impact on the environmental level. EAE has been extensively employed for extracting various target compounds, such as oils, resins, polysaccharides, pigment, medicinal and flavour compounds. Because of increasing demand for natural bioactives to comply with the green extraction principles, pressure has been escalated on the food industry to develop more efficient EAE-based methods as an alternative to the conventional extraction processes. In this chapter, enzymatic applications for phytochemical extraction has been presented (Nadar et al. 2017; Puri et al. 2012).
Utilization of Food Enzymes in Functional Food Development
Broadly, food or food-based products which have significances on human health is considered functional foods (Martirosyan and Miller 2018). Functional foods or food ingredients derived from natural sources impart beneficial health properties as well as lower the side effects associated with unhealthy foods, drugs, and medications (Achi and Asamudo 2018; Zhang et al. 2018; Mishra et al. 2017). Developing functional ingredients by the enzymatic application could be achieved by enzyme-based extraction of bioactive metabolites from target sources and modification of structures of functional compounds by enzymatic catalysis (Gharib-Bibalan 2018). The binding of enzymes with specific site of the substrate corresponds to their catalytic activity (Sagar et al. 2018). An overview of enzymatic application in the food sector is discussed below and pictorial demonstration of the applied avenues of enzymes is shown in Figure 7.1.
FIGURE 7.1 Application of enzymes in different food products.
Fats and Oils Modification
Enzymes play catalytic roles in the modification of lipids which mainly varied from the chemical modifications regarding stereotypic variability, chemo-affinity, and selectivity features (Zhang et al. 2018). Lipases and phospholipases are well- known examples. Oils and fatty acids act as substrates for lipase catalytic activity on lipid modification. Subsequently, fatty acid methyl esters (FAMEs) are generated (Bornscheuer 2018). Another application includes transesterification and synthesis of triglycerides which generates biodiesel and vegetable oil. The isolation of omega- amino carboxylic acids through oleochemical production has been reported with enzymatic cascade reactions (Bornscheuer 2014).
Cereal Products Modification
Carbohydrates are useful food ingredients which act as thickeners, emulsifiers, gelling agents, anticaking agents, humectants, stabilizers, and sweeteners (Cheng et al. 2012). In contrast, carbohydrates can also improve colour and enhance the flavour of products derived from Maillard reactions as well as play roles in the fermentation process (Singh et al. 2016; Voragen 1998). Recently, the use of non- digestible oligosaccharides (NDOs) in the industrial sector is increasing. The recovery of NDOs using enzymatic application mainly involves chemical transformation or extraction process. Galacto-oligosaccharides extraction from soybean through the inulin hydrolysis by endoinulinases were performed to produce commercial fructo- oligosaccharides (Mussatto and Mancilha 2007; Ricca et al. 2007).
Meat Products Modification
Meat is one of the major sources of proteins as well as nutrition (Ryder et al. 2016). Recently, the demand regarding ready-to-eat meat products or artificial meat products has increased (Bekhit et al. 2014; Bhat et al. 2018). The restructuring of meat by transglutaminase occurs through the intra- and intermolecular cross-linking of protein molecules (Bhat et al. 2018; Mora et al. 2014). Therefore, results in the changes in functions of proteins include gelling properties, emulsifying properties, foaming properties, and solubility. The role of transglutaminase on meat restructuring has been reported to enhance the flavour and texture quality (Baugreet et al. 2018). The homogenization process of meats from different sources like beef, pork, and poultry during sausage preparation led to the increased activity of transglutaminase, which results in the changes in texture properties. The exogenous lysine is widely used to manufacture fortified and low-salt meat products (Canto et al. 2014; Kieliszek and Misiewicz 2014).
Dairy Products Modifications
Enzyme-assisted fermented milk products like curd and lactic acid-rich dairy products are increasing consumer demand day by day (de Toledo Guimaraes et al. 2018). The enzymatic application has a crucial role in milk degradation, which generates flavour compounds, amino acids, fatty acids and oligosaccharides (Ano et al. 2018; Khanniri et al. 2016). The commonly used enzymes in dairy products include proteinase, amylase and lipase. Amylases, especially a-amylase and (3-amylase are considered as the major enzymes for milk coagulation process (Patel et al. 2016). The formation of flavours in fermented milk products can be enhanced by proteolytic enzymes. Additionally, in fermented dairy products, the generation of free amino acids from casein and flavours from milk fat can be achieved by the application of lipase and proteinase (Ferreira-Lazarte et al. 2018; Nguyen et al. 2018).
Marine Products Modification
The seafood industry experiences large-scale losses due to temperature fluctuation leading to repetitive freezing and thawing. Therefore, it results in the modification of textural and physiochemical properties (Nikoo et al. 2016). Seafood largely comprises myofibrillar proteins and degradation can easily occur under freezing and thawing conditions and storage temperature irregularity. Recently, cryoprotectants have widely been used in the seafood industry in attempts to lower the denaturation of proteins (Elliott et al. 2017; Jenkelunas and Li-Chan 2018). To extend the shelf life of cryoprotective substances, enzymatic extraction is widely used to extract the target molecules (Nikoo et al. 2016). Gelatin hydrolysates and bioactive peptides derived from enzymatic application act as potential natural cryoprotectants which lower the protein denaturation in marine products (Jenkelunas and Li-Chan 2018; Nikoo et al. 2016; Parvathy and George 2014).