Natural Product Extraction

Principles and Applications

Mauricio A Rostagno, Juliana M Prado

• Publisher: Royal Society of Chemistry
• Year: 2015
• ISBN:
  9781782626220
• Edition: 1
• Topic: Naturwissenschaften
• Subtopic: Industrielle & technische Chemie

Natural products are sought after by the food, pharmaceutical and cosmetics industries, and research continues into their potential for new applications. Extraction of natural products in an economic and environmentally-friendly way is of high importance to all industries involved.

This book presents a holistic and in-depth view of the techniques available for extracting natural products, with modern and more environmentally-benign methods, such as ultrasound and supercritical fluids discussed alongside conventional methods. Examples and case studies are presented, along with the decision-making process needed to determine the most appropriate method. Where appropriate, scale-up and process integration is discussed.

Relevant to researchers in academia and industry, and students aiming for either career path, Natural Product Extraction presents a handy digest of the current trends and latest developments in the field with concepts of Green Chemistry in mind.

CHAPTER 1

Uses and Applications of Extracts from Natural Sources

R. N. CAVALCANTI, T. FORSTER-CARNEIRO, M. T. M. S. GOMES, M. A. ROSTAGNO, J. M. PRADO AND M. A. A. MEIRELES^*

LASEFI/DEA/FEA(School of Food Engineering)/UNICAMP (University of Campinas), R. Monteiro Lobato, 80, Campinas, 13083-862, SP, Brazil

^*Email: [email protected]

Scientific knowledge about the use of natural products with functional properties, consumer demand for high-quality products, as well as legislative actions to reduce the use of synthetic food additives have led to an increase in the use of products from natural sources. This chapter aims to provide context information about the potential commercial uses of extracts from natural sources obtained by various extraction techniques, illustrating their importance in industry and identifying the scope of the techniques and aspects discussed in the following chapters. The main commercial applications of extracts from natural sources discussed here comprise their use as colorants, functional food, nutraceuticals, flavors and fragrances, preserving agents, and edible/non-edible oils and fats applied to cosmetic, pharmaceutical and food industries. However, due to their nature, natural products are complex and therefore several aspects must be considered for each application, including importance, chemical characteristics of main compounds present and possible mechanisms of action.

1.1 Introduction

Current scientific evidence about physiological, nutritional, and medicinal benefits to human health provided by the use of natural products, as well as the potential harmful effects from the use of synthetic products and consequent legislative actions restricting their use, has motivated a significant increase in the consumption of natural products.¹ In this context, extracts from natural sources play an important role as natural additives or industrial inputs to food, cosmetic, textile, perfumery, and pharmaceutical industries (Figure 1.1), influencing many characteristics of the final product. Indeed, the majority of natural extracts have more than one or two functions. They have been used as natural colorants, nutraceuticals, functional foods, preserving agents, flavors and fragrances, edible oils and fats, drugs, vitamin supplements, chemical standards, and perfumes, among others. The major natural extracts are obtained from plant sources such as seeds, leaves, flowers, berries, barks, and roots, although some of them may be obtained from animal sources such as carmine dye from female insect cochineal (Dactylopius coccus), honey from bees, squalene from shark liver, etc.

Figure 1.1 Uses and applications of extracts from natural sources.

The applications of natural extracts are generally associated with the functionality derived from their active components. Usually, functional foods are obtained by enrichment with functional compounds, which are ingredients able to promote or provide a beneficial effect on human health. These compounds may also be concentrated, serving as nutritional supplements, known as nutraceuticals, which are commercialized as tablets and capsules.¹ They may also be used for technological roles, as coloring agents, conservation agents, etc., and for the production of chemicals.^2,3

Many of the bioactive properties assigned to functional foods and nutraceuticals are provided by compounds derived from the secondary metabolism of plants, also called phytochemicals. ‘Phytochemicals’ literally means chemicals produced by plants; they play an important role in plant metabolism.⁴ Phytochemicals are not established as essential nutrients, but may have a great biological significance.⁵ In most cases they are ingested by humans as part of the diet, including in fruit, vegetables, beans, and grains, in beverages such as juices, green or black tea, coffee, etc. There are several phytochemical classes, including polyphenols (flavonoids, phenolic acids, tannins, stilbenes, coumarins, and lignans), carotenoids, phytosterols, alkaloids, terpenes, and sulfur-containing compounds (sulfides and glucosinolates).⁶ Although there is already sufficient scientific evidence pointing to the association between effects beneficial to human health and phytochemical intake, the mechanisms of action are not yet fully elucidated. Furthermore, it is believed that many of these beneficial effects are the result of additive and/or synergistic phenomena of these compounds, being attributed to the complex mixture of phytochemicals rather than to a single compound.^7–10 Products with phytochemical compounds have many other applications in food and other industries, including pharmaceutical, cosmetics, perfumes, and textile industries. For example, many products of personal care include a wide variety of natural products in their formulation including soaps, shampoos, sunscreen, hair dye, make-up, toothpaste, deodorants, etc.^11–14

1.2 Uses and Applications

There are many uses of extracts from natural sources which can be grouped according to their technological role: coloring agents, functional food, nutraceuticals, preserving agents, flavors, fragrances, and edible oils.

Coloring agents or color additives are any pigment, dye, or substance that produces color when it is added to a product. The coloring agents may be found in liquid, solid, semi-solid, or gel forms. Due to the large availability of food coloring agents there are several other non-food applications that explore their properties, including cosmetics, pharmaceuticals, and medical devices. Natural colorants are extracted by various processes and classified according to their color, chemical composition/structure, biological function in plant/body (chlorophyll, hemoglobin, etc.), and physical properties (solubility). The main dyes from plant sources are red (Brazil wood, sugar, etc.), orange (saffron flower, Crocus sativus), yellow (chamomile, Anthemis tinctoria), green (ragweed, Ambrosia artemisiifolia), and blue (indigo, Indigofera tinctoria). The main food dyes from animal sources are sepia (cuttlefish bag), red (kermes lice), and purple (murex shellfish).¹⁵

Besides the technological function of several well-known natural coloring agents, the phytochemicals may have other biological functions and play a role on the prevention of diseases.^16–19 Functional foods, nutraceuticals, food supplements, and antioxidants belong to an economically important sector of the global food market.^20–24 Examples of potential applications include reducing the risk of cardiovascular disease, cancer, diabetes, inflammation, and osteoporosis. Among the various functional effects, it is important to highlight the effects on gastrointestinal functions and hormonal modulation.^25–27

Furthermore, preserving agent activity, antibacterial activity, and antifungal activity also represent an economically important sector of the global natural products market. Certain types of food preservatives are needed to ensure the quality of the final product. Most chemical preservatives widely used are weak organic acids (e.g. ascorbic acid and benzoic acid) used in synergistic combinations.²⁸ In this case, the antimicrobial and antifungal properties of essential oils are considered to be the most important.²⁹

1.2.1 Coloring Agents

Highly conjugated systems which absorb electromagnetic radiation between wavelengths of 400 nm to 800 nm appear to be colored. Color can provide a pleasant aspect to the substrate as well as express emotions and ideas.³⁰ Color is often the first notable sensorial characteristic that influences the expectations of consumers and also influences quality-related decisions during visual inspections.^31,32 Color plays an important role in quality perception indicating our expectations, perceptions, susceptibilities to, and preferences for products, as it is used to indicate good quality, to assist marketing, and to satisfy consumers.³³ The color of food, pharmaceutical, and cosmetic products can be the result of natural pigments present in the matrix used; coloration formed upon heating, processing, or storage; or the addition of natural or synthetic colorants.³² Colorants or color additives are the terms for all soluble or solubilized coloring agents (dyes or pigments), as well as insoluble pigments, employed to impart color to a material.³¹ The mechanism of color production is due to a molecule-specific structure (chromophore) of chemical compounds that absorbs light in the wavelength range of the visible region known as pigments. Those chromophores capture energy and the excitation of an electron from an external orbital to a higher orbital is produced; the non-absorbed energy is reflected and/or refracted to be captured by the eye, and neural impulses are generated, which are transmitted to the brain where they can be interpreted as a color.³⁴

Coloring agents can be defined by their origin as natural, synthetic, or inorganic colorants. Natural pigments are produced by living organisms. Synthetic colorants or dyes are synthetized by chemical reactions. Inorganic pigments can be found in nature or can be reproduced by synthesis.³⁴ Synthetic organic dyes have been recognized for many years as the most reliable and economical coloring agents because they are superior to natural pigments in tinctorial power, consistence of strength, range, and bri...

Table of contents

• Cover
• Title
• Copyright
• Preface
• Contents
• CHAPTER 1 Uses and Applications of Extracts from Natural Sources
• CHAPTER 2 Extraction of Natural Products: Principles and Fundamental Aspects
• CHAPTER 3 Ultrasound-assisted Extraction
• CHAPTER 4 Microwave-assisted Extraction
• CHAPTER 5 Accelerated Liquid Extraction
• CHAPTER 6 Supercritical Fluid Extraction
• CHAPTER 7 Recent Trends and Perspectives for the Extraction of Natural Products
• CHAPTER 8 Post-extraction Processes: Improvement of Functional Characteristics of Extracts
• CHAPTER 9 Isolation and Purification of Natural Products
• CHAPTER 10 Scale-up of Extraction Processes
• CHAPTER 11 Integration of Pressurized Fluid-based Technologies for Natural Product Processing
• CHAPTER 12 Economic Evaluation of Natural Product Extraction Processes
• Subject Index