Consumer Guide to Herbal Oils

INTRODUCTION

Herbal oils, also called plant oils, represent combined fraction of fat soluble (liposoluble) ingredients obtained from seeds, fruits, flowers, roots, bark or leaves. They contain wide range of components such as fatty acids, vitamins and vitamin-like compounds, antioxidants, phytosterols, carotenoids and other nutrients. Plant oils are utilized in food, personal care products and herbal medicines since prehistoric times.

The composition and properties of herbal oil are determined by the source (type and part of herb used), as well as the way of manufacturing. Herbal oils may be divided into three major types with different manufacturing technologies and consequently properties:

1. Essential or Aromatic Oils
2. Vegetable or Seed Oils
3. Herbal Oil Extracts

Each type of oils has common features in composition, properties and areas of applications. It is important to remember that one plant may be a source of two or more types of herbal oils depending of what part of plant is used and what manufacturing method is employed. Knowing the type of herbal oil will help to evaluate potential health and nutritional benefits and determine proper ways of handling, storage and application. This review is intended to help understand the differences between various types of herbal oils.

ESSENTIAL OILS

Essential oil is a mixture of volatile (air soluble) or fragrant ingredients present in the herb. Essential oils are also called herbal essences, aromatic essences or fragrant essences. Usually these essences are not soluble in water but freely dissolve in the oil. Many essential oils were discovered long ago, before or during medieval times and used since then in cooking, medicinal or cosmetic purposes. Traditionally essential oils have been obtained via steam distillation of raw herbal material, today other methods are also used, such as liquid or supercritical carbon dioxide (CO2) extraction. When using steam distillation, raw herb is boiled in the water, volatile ingredients are evaporated and carried away along with water steam. Essential oils are separated from the water after cooling down and condensation back into the liquid phase, since they do not mix with water in the liquid phase.

While most herbs usually has some volatile ingredients, only some contain enough and possess useful properties to make practical their extraction and utilization. Essential oils are used as aromatic ingredients in food, cosmetics, fragrances and personal care. A number of essential oil have been used in aromatherapy and some have proven medicinal properties including antibacterial, antiviral, anti-inflammatory, digestive, calming, relaxing and others. Essential oils are almost never applied in undiluted form due to their ability to irritate and in some cases burn the skin and mucous. They are usually used in percent ( 1/100 ) to parts of percent concentrations. Because of their high cost essential oils are frequently substituted with synthetic imitations, called artificial flavors and odors. While these synthetic fragrances do impart similar aroma, they do not usually produce similar biological or medicinal action as natural essential oils.

Every essential oil is usually a combination of dozens to hundreds volatile ingredients with different chemical structure and properties. In some oils there is one or few components which constitute the majority of the oil mass and are responsible for its flavor and most important characteristics. For example, Lemon (Citrus limon) essential oil, obtained from lemon peel contains more than 60% of limonene, Peppermint ( Mentha piperita) essential oil contains more that 60% of combination of menthol and menthone, and Eucalyptus ( Eucalyptus globulus) essential oil contains more than 60% of cineol. These major components are frequently additionally purified and used as ingredients in industrial manufacturing, menthol is one of the most well known examples.

VEGETABLE OILS

Vegetable oils are the most common type of plant oils extensively used in food and personal care products. Obtained primarily from seeds or nuts, like olive oil, almond oil, sunflower oil they were called in earlier times fixed oils to emphasize the difference from volatile essential oils. Raw vegetable oils are the combination of all fat soluble (liposoluble) ingredients of the herb. They are primarily composed of fatty acids triglycerides, which include wide variety of essential and nonessential fatty acids, and may contain organic spirits, phytosterols, phospholipids, polyphenols, tocopherols (vitamin E), tocotrienols, plant waxes and other minor ingredients. Vegetable oils serve as important dietary source of essential fatty acids (EFA), which human body cannot synthesize but requires for important functions. There are dozens of different EFA, and various vegetable oil may share in part their EFA content. Apparently only several EFA are required in human diet as body is able to transform one EFA into another.

Vegetable oils are obtained from seeds and nuts with the aid of press, expeller, or in some cases using organic solvents extraction. Freshly obtained raw vegetable oils may contain as minor ingredients colors, flavors, free fatty acids, fragments of plant material such as protein agglomerates, fiber etc, as well as waxes, phytosterols and agrochemicals. Such raw oils are called unrefined. Many minor ingredients are low or not soluble in oil and make oil appearance cloudy, they also make oil less suitable for cooking. In commercial manufacturing these ingredients are usually removed with the aid of filtration, centrifugation, bleaching and sometimes organic solvents. Depending of the composition of fatty acids in the vegetable oil, such as percentage of essential fatty acids and content of long chain versus short chain fatty acids as well as presence and proportion of such ingredients as phytosterols, phospholipids and waxes, it may come up as liquid, semi liquid or solid form. Since, liquid oil is more suitable for commercial distribution, components with low solubility are usually removed from the oil during manufacturing process. Obtained transparent liquid oil with no sediments, is called refined vegetable oil.

Vegetable oils are produced at room or above room temperatures but usually are stored at below room temperatures to extend their shelf life. Oil components with lower solubility have a tendency to precipitate at lower temperatures. This makes the oil look cloudy, in some cases separate in layers, have sediments or pellets in the bottom and as a result lose its commercial appeal. To resolve this problem raw vegetable oils (called sometimes virgin oils) are intentionally exposed to lower temperatures to cause the precipitation of low temperature sensitive ingredients. The clear transparent product obtained after the removal of precipitated ingredients via centrifugation or filtration is called winterized oil. The winterized oil in comparison to raw or virgin oil is depleted in certain minor ingredient, such as phytosterols, herbal waxes, long chain spirit esters, and some others.

Refined winterized vegetable oils can be stored at lower temperatures for a long time. They are distributed as consumer food products, sold in grocery stores and used in food and personal care manufacturing.

About Floraleads Herbal Oils

HERBAL OIL EXTRACTS

If liposoluble ingredients content in the plant is only few per cents or less they cannot be expressed or expelled with the aid of press or expeller. Instead they may be dissolved, extracted and separated from the plant material with the help of appropriate solvent. A mixture of liposoluble herbal constituents extracted and separated from the herb into appropriate solvent is herbal oil extract. Traditionally herbal oil extracts were produced by extracting raw herbs into vegetable oil, called for this purpose carrier oil. The vegetable oil is employed as a solvent to dissolve, extract and separate (carry away) fat soluble ingredients from the herb. The extraction process yields liquid product, called herbal oil extract, comprising liposoluble herb ingredients dissolved in the carrier oil. Herbal oil extracts were obtained in this way and utilized in cosmetic preparations and herbal medicines for thousands years. Infused oils are herbal oil extracts with apparently low content or herbal constituents, which are usually obtained by exposure of relatively small quantity of herb in the carrier oil, and used in food making or as digestive aids. Although herbal oil extracts have been used in medicines and personal care for a long time there are few studies of this type of plant oils. Available historic records represent the main body of our knowledge about the properties of herbal oil extracts. Only in recent decades scientists have begun to isolate individual fat soluble ingredients of herbs and study their biological action and nutritional value.

Significant increase in consumption of herbal oil extracts and certain liposoluble herb ingredients during 19 and 20-th centuries could not be satisfied by traditional slow and tedious extraction with vegetable oil. High demand initiated development of new large scale industrial technologies, including extraction with organic solvents, extraction with liquid or supercritical carbon dioxide (CO2) and others. Organic solvents such as hexane, benzene, acetone, ether and ethyl acetate have been used for commercial extraction of liposoluble herbal ingredients. These solvents allow high speed, large scale extraction and may be separated from isolated material by subsequent evaporation under low pressure. Besides being the leading technology of modern production of herbal oil extracts and some vegetable oils, large scale organic solvent extraction is utilized in isolation and purification of many individual herbal ingredients with commercial value. Fat soluble vitamins, numerous carotenoids, flavonoids, polyphenols, phytosterols and other nutrients were discovered and isolated from herbal oil extracts. Extraction with liquid or supercritical CO2 is also utilized in commercial manufacturing to obtain large amounts of fat soluble herbal ingredients. It is rather expensive, but much safer and yields product which has not been in contact with organic solvents, and therefore has less chances to be contaminated.

While modern industrial technologies made herbal oil extracts more available, they have also transformed their chemical composition. Indeed, the composition of ingredients in extracts obtained with organic solvents, CO2 or vegetable oil from the same herb in most cases is not identical. This makes it difficult to apply data obtained or effects observed with one kind of extract to another. For example, one of the most obvious differences is the absence of volatile ingredients in extracts obtained with organic solvents or CO2. In fact, manufacturing of herbal oil extracts using organic solvent or CO2 requires removal of the solvent after the extraction procedure using evaporation under low pressure and/or elevated temperature. This process removes volatile herbal ingredients from the extract along with the solvent. Therefore, the herbal oil extract produced using traditional oil extraction process will usually have specific aroma, while organic solvent or CO2 extract are nearly always odorless. Furthermore, herbal extracts obtained using organic solvent or CO2 frequently present itself as a solid or semisolid matter after evaporation of the solvent. To be utilized for the manufacturing of personal care, food or cosmetic products it has to be transformed into stable liquid form. This requires additional processing, including dissolution in appropriate solvents and removal of insoluble and particulate components, which may cause significant reduction or even loss of certain ingredients. Finally, as mentioned above, extracts obtained with organic solvents may contain residual amounts of these solvents.

Herbal Oil Products

PRODUCT EVALUATION

Herbal oils in dietary supplement and personal care products are frequently associated with health or nutritional claims. To evaluate the validity of these claims it is important to know the type of oil, since several types of herbal oils with different properties may be obtained from the same plant. As shown above, essential oils, vegetable oils and herbal oil extracts, each offer distinctive array of ingredients and specific applications in nutrition, personal care and medicine. Consequently, information about the type of herbal oil used in particular product may suggest if this product may or may not offer desirable effect. Essential oils are usually utilized in fragrances, aromatizes, or flavoring food additives. A number of essential oils are known for their health beneficial action and have been traditionally used as active ingredients in herbal medicines. These medicinal effects are unique for each particular herbal essence and are not duplicated in artificial fragrances. Vegetable oils are mostly used as cooking oils, food ingredients and also ingredients in personal care products with moisturizing and restorative action. Many vegetable oils are valuable dietary source of essential fatty acids, which human body can not produce, but requires for normal functions. Herbal oil extracts are traditionally used in herbal medicines and personal care products. They contain numerous biologically active ingredients some with defined health beneficial properties and others we only begin to comprehend.

Following example illustrate the importance of recognizing what type of herbal oils is utilized in the product. One of most well known herbs in personal care and dietary supplement area is Rose. Three types of plant oils are produced from Rose, each with different qualities:

Essential oil: Rose essential oil.
Rose essence is yellow volatile oil with deep sweet characteristic aroma obtained by steam distillation of Rose buds and/or petals. Main ingredients are citronellol, phenyl ethanol, geraniol, nerol, stearopten, and up to 300 other ingredients. Widely utilized fragrance ingredient and in personal care products to address wide range of skin conditions, such as eczema, herpes, wrinkles, broken capillaries, dry skin and others. Traditional medicinal use includes digestive circulatory, respiratory problems, nervous tensions, headaches and depression.

Vegetable oil: Rose hip seed oil.
The seed oil is obtained by cold press extraction or solvent extraction of seeds of Rose Hip. May be yellow to light red color depending of the presence of small amounts of carotenoids. Valuable dietary source of EFA, accounting for 80 - 90% of the oil. Most nutritionally valuable EFAs include Omega 6 (Linoleic, C18:2) up to 45 %, Omega 3 (Linolenic C18:3) up to 35%, and Omega 9 (Oleic, C18:1) up to 15 %. Minor ingredients include numerous fatty acids, trans-retinoic acid and several carotenoids, tocopherols. Rose hip seed oil is primary a good dietary source of essential fatty acids, especially Omega 3 and Omega 6.

Herbal Oil Extracts: Rose hip oil extract or Whole Rose hip oil extract.
Oil extract is obtained by extraction of dry Rose hip into carrier vegetable oil, usually olive oil. Oil of red to dip red color with specific herbal aroma. Rose hip oil extract is a rich source of numerous liposolube antioxidants, trans-retinoic acid and a number of carotenoids, criptoxantin, taroxantin, flavonoids including quercetin, catechins, tocopherols and tocotrienols. Rose hip oil extract has been used for hundreds of year and currently is widely popular as skin care product and herbal medicine. It is applied as restorative anti-aging skin treatment to address such conditions as eczema, brown spots,wrinkles, scars, broken capillaries, dry skin and treat wound, burns, bed sores and skin ulcers.

Many herbs are utilized to make two or more types of herbal oils.