Recent Advances in Biotechnology

The present book chapter deals with recent advances in food protein biotechnology. The latest research on food protein-derived bioactive peptides and the impact of enzymatic hydrolysis on the organoleptic properties of proteins is reviewed. Protein modifications, which have become the focus of many research studies during recent years, are also covered. Consideration is given to three different protein modification approaches (i) chemical modifications (glycation and disulfide crosslinking); (ii) physical modifications (high-pressure processing and ultrasound treatment); (iii) enzymatic modifications (transglutaminase cross-linking and proteolysis). Since the main purpose of protein modification is to enhance their functional properties, the effects of the chemical, physical, and enzymatic treatments on the solubility, emulsification, foamability, and rheological properties of food proteins are also discussed.

Exopolysaccharide (EPS) production has been reported in both prokaryotes and eukaryotes. Bacterial EPSs have been used in both food and non-food applications. The demand for these EPSs has increased in the last two decades due to various advantages associated with these biopolymers compared to other plant and animal based hydrocolloids. Synthesis mechanism, structure, and characteristics of EPS vary with species of bacteria. Different methods of isolation and characterization of bacterial EPS have been reported. EPSs of bacteria have various technological properties, which suit their application in various industries. This chapter discusses the classification of EPS, EPS-producing bacterial species, biosynthesis of homopolysaccharides and heteropolysaccharides, extraction and purification of EPS, characterization of EPS, functional properties and various food applications of EPSs, and health benefits of EPSs.

Phospholipids (PLs) are naturally-occurring amphiphilic compounds, which can be used as emulsifiers, liposome components, and nutritional supplements in food, cosmetic, and pharmaceutical industries. Enzymatic modifications of natural PLs are of importance to enhance the quality of PLs as value-added products. This chapter reviews the advances in the enzymatic modification of PLs, including acyl group modification and head group modification. Acyl group modification can be performed using lipase- or phospholipase A-mediated transesterification or ester synthesis to introduce particular fatty acid residues. Head group modification is carried out by phospholipase D-catalyzed transphosphatidylation. This reaction enables introduction of a wide range of natural and unnatural functional molecules into the phospholipids, making it possible to prepare chemically defined structured PLs for diverse applications.

Many food products are fermented and this can be for several reasons including taste, shelf-life extension, and improvement of the nutritional value. During the fermentation, the present carbon source is typically converted into organic acid or alcohol. The main fermenting microorganisms are lactic acid bacteria, yeasts and filamentous fungi. Different categories of food products and the benefits that the fermenting microbes bring to these products are discussed. Moreover, there is an emphasis on health-promoting microorganisms, on the mutual effects that microorganisms have on each other, and the resulting effects on the food matrices. Besides, the current and future status of culture research, culture production, and their impact on food fermentation are discussed.

Evidence has shown that human gut microbiota has an important effect on many aspects of human physiology including metabolism, nutrient absorption and immune function. Perturbation of the intestinal microbiota could lead to chronic diseases, such as inflammatory bowel diseases, obesity, diabetes, and colon cancer. Modulation of the microbiota by dietary interventions, especially by the use of probiotics, prebiotics and synbiotics has shown its potential for the treatment and prevention of diseases. Hence, the number of studies aimed to research the therapeutic effect of probiotic strains and prebiotics as well as the molecular mechanisms involved in the modulation of microbial populations and their environment by dietary intervention had increased considerably in the last 10 years. On the other hand, the current omics technologies are providing the tools needed to examine the community structure and function of the gut microbiota and therefore, understand its role in health and disease. The aim of this chapter is to provide a comprehensive overview of the research carried out on probiotics, prebiotics and synbiotics in the last 10 years as well as present the new biotechnologies that are contributing to the understanding of the host-microbiota interactions and the mechanisms of actions of pro-, pre- and synbiotics.

Food additives are substances incorporated into foods to improve quality, nutritional value, functional properties, and consumer acceptance. There is a tendency to replace synthetic additives by natural ones not only because of toxicity of the first but also because natural additives can enhance the characteristics of foodstuff. In this sense, the use of bioprocess technologies can improve the production of natural substances by using wild or genetically modified microorganisms, metabolic engineering, or simply by developing new food formulations. The major goal of this chapter is to present the main food additives used nowadays, mainly focusing on the ones produced via biotechnology. The food additives discussed include amino acids, antimicrobial peptides, colorants, organic acids, vitamins, and sweeteners. Although there are many food additives biotechnologically produced on research level, a lot of effort is required to improve their production yields and reduce their overall cost, enabling their large industrial production and commercialization. Anyway, food additives need to be approved by the regulatory authorities before they become industrially favorable. Despite this, biotechnology seems to be very promising in producing natural food additives. Some of the advances in this area are described in the present chapter.

Two thousand and five hundred years ago, Hippocrates stated ‘let food be the medicine and medicine be the food’, but only in 1989, Stephen DeFelice coined the term nutraceutical to describe the hybrid between ‘nutrition’ and ‘pharmaceutical’. A ‘nutraceutical’ is defined as a supplement to the diet that is composed of bioactive compounds found in foods and botanicals, vitamins, and minerals. It is formulated and taken under the form of capsules, tablets, etc., resulting in beneficial health impacts. Owing to their biological properties, phenolic compounds are considered nutraceuticals with great potential; however, their effects are limited due to their low bioavailability. The rationale for developing an efficient drug/nutraceutical delivery system is to increase the bioavailability and half-time of the drug in the vicinity of the target cells, reducing at the same time, its exposure to non-target cells. Nutraceutical delivery to the brain is a major challenge imposed by physical barriers, such as the blood-brain barrier (BBB). In the last decade, nanotechnology has become a powerful strategy to enable nutraceuticals’ target-delivery to tissues and organs, including the brain. This chapter will present the latest results obtained with phenolic-based nanoparticles, showing the failures, achievements, and most promising routes for future works.

Enzymes have a vital role in adding value to milk, and their function varies widely from coagulants used to make cheese, to bioprotective enzymes used to enhance the shelf-life of dairy products, proteases used for acceleration of cheese ripening and modification of functional properties of milk proteins, lipases used to develop lipolytic flavors in cheese ripening, and lactases used to hydrolyze lactose to alleviate lactose intolerance and produce galactooligosaccharides as dietary fibers. This chapter (i) presents the recent advances in enzyme discovery approaches used to search for novel enzymes with interesting features, supported by few examples of relevance to the dairy industry, and (ii) discusses the up-to-date developments in industrial dairy enzyme applications, with particular focus on lactose bioconversion by lactose hydrolysis and transgalactosylation.

In recent years, the application of biotechnology on residues or by-products of food processing industries has received great interest from researchers, since the production of bulk chemicals and high value-added compounds, such as ethanol, biogas, organic acids, enzymes, mushrooms, etc. has been investigated in detail. The utilization of these abundant residues as alternative nutrient sources for microorganisms’ growth is also expected to minimize both environmental pollution from their disposal and the final production cost of bio-products. The main objective of the present chapter is to highlight the role of biotechnology on the bioconversion of major industrial and agro-industrial by-products, that have zero acquisition cost, to produce various bio-products.

Genetics is the science of studying genes that are organized and compacted into nucleosomes and chromatin. Several cases, involving the incorporation of important genes or knocking out others, have been used over the last decades in crop and food applications. Because genetically modified crops are banned and/or ethically under debate, epigenetics that studies gene regulation is thought to have an impact on crop production in future applications. Epigenetics refers to the study of heritable changes in gene expressions without changes in the gene sequence. Epigenetics regulation of gene expression is applied by histone modifications, DNA methylation, histone variants, chromatin remodeling, and small RNAs. This chapter describes what becomes known in plant epigenetics, and future expectations that can employ epigenetics in order to improve crops and produce higher levels of vitamins and proteins that are important for food production and human health.