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Factors Affecting the Bioaccessibility and Bioavailability of Bioactive Compounds
Bioactive compounds are found in fruits, vegetables and whole grains. They include an extremely heterogeneous class of compounds (polyphenolic compounds, carotenoids, tocopherols, phytosterols and organosulfur compounds) with different chemical structures (hydrophilic or lipophilic), distribution in nature (specific to vegetable species or ubiquitous), range of concentrations both in foods and in the human body, possible site of action, effectiveness against oxidative species, and specificity and biological action.
Several factors interfere with the bioavailability of antioxidants, such as food source and chemical interactions with other phytochemicals and biomolecules present in the food include some of the factors interfering with the bioavailability of bioactive compounds. For example, fruit antioxidants are commonly mixed with different macromolecules such as carbohydrates, lipids, and proteins to form the food matrix. In plant tissue, carbohydrates are the major compounds found, mainly in free and conjugated forms.
After consumption, the nutrients that are present in a food or drink are released, absorbed into the bloodstream and transported to their target tissues. Different nutrients differ in their bioavailability, which means that they are not utilized to the same extent. Release of the nutrient from the food matrix, effects of digestive enzymes in the intestine, binding and uptake by the intestinal mucosa, transfer across the gut wall to the blood or lymphatic circulation, systemic distribution and deposition, metabolic and functional use, excretion can affect nutrient bioavailability. It is mediated by external (e.g. characteristics of the food matrix, chemical form of the nutrient etc) and consumer internal (e.g. gender, age, nutrient status and life stage) factors. The bioavailability of macronutrients (carbohydrates, proteins and fats) is usually very high, e.g. more than 90% of the amount ingested.
Bioaccessibility is the first step for making a nutrient bioavailable. In this step, the nutrient is liberated from the food matrix and turn into a chemical form that can bind to and enter the gut cells or pass between them. Chewing, enzymatic digestion of the food in the mouth, mixing with acid and enzymes in the gastric juice and release into the small intestine, are the unit operations of the process by which the nutrients are rendered bioaccessible. The small intestine is the major site of nutrient absorption. Enzymes of the pancreatic juice continue breaking down the food matrix. Certain procedures involved in food preparation like cooking, chopping or pureeing collaborate with mastication and enzymes, to the digestibility of food matrices.
The oral bioavailability of bioactive compounds is drastically affected by the restricted release of compounds from plant matrix, the solubility in gastrointestinal fluid, the permeability across intestinal epithelial cells, as well as the enzymatic and chemical reactions occurring within the gastrointestinal tract. Four essential steps are necessary for the effective absorption of bioactive compounds:
- Release the from food matrix,
- Incorporation into bile-salt micelles,
- Absorption by epithelial cells, and finally
- Incorporation into the chyclomicrons with secretion into lymphatic system.
Food processing has an impact on the chemical constituents as well as on the physical and sensory properties of the final product. Applied technologies may influence the content of bioactive compounds leading to changes in their functional properties (e.g. bioavailability, bioaccessibility and bioactivity) and potential health benefits. Indeed, loss of phytonutrients foods becomes more and more significant as foods are processed, stored and transported. Therefore, attention should be given to the degree of disintegration of the initial tissue structure because of its impact on food quality, functionality and deterioration. As the demand for functional food increases, intense research efforts for the development of new processing technologies is conducted with the ultimate goal of ensuring maximal nutritional and functional properties, as well as the overall quality of a product.
Nutraceutical and Functional Food Components: Effects of Innovative Processing Techniques presents the latest information on the chemistry, biochemistry, toxicology, health effects, and nutrition characteristics of food components and the recent trends and practices that the food industry (e.g. the implementation of non-thermal technologies, nanoencapsulation, new extraction techniques, and new sources, like by-products, etc.) has adopted. This book fills the gap in knowledge by denoting the impact of recent food industry advances in different parameters of food components (e.g. nutritional value, physical and chemical properties, bioavailability and bioaccessibility characteristics) and final products (e.g. applications, shelf-life, sensory characteristics).
- Provides a holistic view of the interactions between novel processing techniques and food components
- Explains how innovative techniques, such as non-thermal, nano-encapsulation, waste recovery, and novel extraction and processing methods impact the nutritional value of ingredients commonly used in functional food and nutraceutical products
- Covers food applications, shelf-life, and sensory characteristics
Charis M. Galanakis is an interdisciplinary scientist with a fast-expanding work that balances between food and environment, industry, and academia. His research targets mainly the separation and recovery of functional macro- and micromolecules from different food by-products, as well as their implementation as additives in food and other products. He is the research and innovation director of Galanakis Laboratories (Chania, Greece) and the coordinator of Food Waste Recovery Group of ISEKI Food Association (Vienna, Austria).
He serves as an editorial board member and subject editor of Food and Bioproducts Processing and Food Research International, and he has edited 6 books from Academic Press: Food Waste Recovery: Processing Technologies and Industrial Techniques (2015), Innovation Strategies in the Food Industry: Tools for implementation (2016) and Nutraceutical and Functional Food Components: Effects of Innovative Processing Techniques (2017), Olive Mill Waste: Recent advances for the Sustainable Management (2017), Handbook of Grape Processing By-Products: Sustainable Solutions (2017) and Handbook of Coffee Processing By-Products: Sustainable Applications (2017).
See his full portfolio of books here.
Charis’ latest books are available to order on the Elsevier Store. Use discount code STC317 at checkout and save up to 30% on your very own copy!
Food Science & Nutrition
The field of food science is highly interdisciplinary, spanning areas of chemistry, engineering, biology, and many more. Researchers in these areas achieve fundamental advances in our understanding of agriculture, nutrition, and food-borne illness, and develop new technologies, like food processing methods and packaging material. Against a backdrop of global issues of food supply and regulation, this important work is supported by Elsevier’s catalog of books, eBooks, and journals in food science, considered essential resources for students, instructors, and health professionals worldwide. Learn more about our Food Science and Nutrition books here.