JOURNAL OF COSMETIC SCIENCE 188 fragmentation, and loss in biodiversity (3,4). Therefore, research into alternative sources of bio-based chemicals is needed. Another large impact of human activities on our planet is the production of food and re- sulting associated waste, such as organic food-waste streams. Studies suggest that food production needs to increase dramatically to keep pace with projected demands from population growth, dietary change (meat use), and increasing bioenergy use (5,6). Al- though several potential solutions to these problems are being investigated, food produc- tion also generates large food waste streams that should be better exploited. If these wastes can be converted into profi table biomass, then the ecological burden that waste poses may decline. Insects may contribute to the development of this circular economy, and they already fi nd implementation in the food and feed sectors. Although insect consumption is com- mon in large parts of the world, this is not an established practice in the western world. However, insect consumption may have a large impact on food/feed-associated prob- lems, and therefore, work is done to demonstrate the potential of edible insects to the regulatory agencies (7). Another application of insects can be as a source of biomaterials, such as fats, proteins, and chitin. These broad fractions of biomaterials may fi nd diverse use in the industry (chemical). Coupling the breeding of the insects to waste stream reduction (8), insects may become a sustainable alternative in the production of biomaterials, such as fats and oils. An example is the work being done on the black soldier fl y (BSF, Hermetia illucens). BSF are relatively easy to breed in large quantities on small surfaces. The larvae can be easily bred on organic waste streams (9) and the resulting fats are being explored for their potential use in biofuels (10,11). Also chitin, extracted from BSF, can be modifi ed into chitosan. This molecule has antimicrobial activity that may fi nd application in several areas, including food and nutrition biotechnology material science and pharmaceuticals (12). Other insect species that are commonly investigated are the house cricket (Acheta domesticus) and the locust (Locusta migratoria) (13). The house cricket is usually grown on pet food (fi sh food/cat food) under lab conditions, but they can also be bred on organic vegetable wastes. Locusts are bred on grass, which may pose an issue for breeding during winter in northern countries, but still, a case can be made to use locusts in the reduction of the large amounts of grass waste that are produced yearly with no relevant application. Fats and oils are commonly used in cosmetics, where they are a major component of creams for skin care. Triglycerides typically act as emollients that soften the skin (14). Indirectly, they will also moisturize the skin by reducing the transepidermal water loss (TEWL) (15). Depending on the fatty acid profi le, the properties of the fats can vary and the healing (e.g., using linoleic acid for dry skin) or skin-protective functions of the creams can be enhanced. The fats are also used to increase the viscosity of the formulation or for their emulsifying properties (16). From a skin-care point of view, mink-fats have a favorable fatty acid profi le and have therefore been traditionally used in many skin-care formulations. Although the mink oil can be seen as a side stream derived from mink fur industry, ethical objections arise toward the use of minks for their fur. Other sources of useful fats need to be explored. Macadamia nut oil, which has a similar fatty acid profi le as mink oil, has been shown to present a suitable source of oils for cosmetics. However, issues may arise with the use of edible oils cultivated on valuable land for nonfood/feed

INSECT FATS FOR COSMETICS 189 applications and transport and associated costs. Therefore, identifying other suitable sources such as insect fats may prove useful. In this paper, three insect species, the BSF, the house cricket and the locust, were evalu- ated for their potential use in cosmetic applications. Fats extracted from these insects are evaluated in a hand cream formulation as a proof of principle to demonstrate the potential of using insects, cultivated on organic waste streams, in personal health-care products. MATERIALS AND METHODS INSECTS In general, insects are considered as farm animals and are to be treated as such according to the Belgian legislation (17). However, detailed guidance regarding insect welfare and euthanasia are lacking and little is known about the humane treatment and other ethical aspects in insects. Black soldier fl ies were bred at the Thomas More campus Geel in a greenhouse at an average day temperature of 30°C and relative humidity of 50–90%. The breeding process is similar to the process described in Sheppard et al.(18). Female fl ies deposit their eggs in cardboard structures. Eggs were harvested and placed shielded from light until they hatched. For this study, the larvae were cultivated on chicken feed. When they reached the pre-pupae stage, the pre-pupae migrated out of the chicken feed and were harvested. The pre-pupae were stored at -20°C until needed for fat extraction. Locusts and crickets were bought frozen from a local insect breeder (Desmedt Insects, Tessenderlo, Belgium). CHEMICALS AND FATS All chemicals, citric acid, sodium hydroxide, hexane, chloroform, propanol, diethyl ether, methanol acetic acid, phenolphthalein, Fuller’s earth, ethyl acetate, petroleum ether (40–65°C), NaCl, BF3, 2,2,4-trimethyl heptane, Na2SO4 used for the extraction, degum- ming, thin-layer chromatography (TLC), and gas chromatography–mass spectrometry (GC–MS) procedures were bought from Sigma-Aldrich (St. Louis, MO) and VWR Chemicals (Radnor, PA). Macadamia nut oil and a commercial vegetal oil mixture (a mixture of macadamia nut oil, cotton seed oil, and olive derived squalene) were purchased from IMCD Benelux BV (West-Knollendam, The Netherlands) and Clariant (Puget-sur-Argens CEDEX, France), respectively. EXTRACTION OF INSECT FATS Fats were extracted from all three insect species. The insects were dried, typically over- night at 65°C, and subsequently ground and sieved (maze 2.36 mm). A Soxhlet procedure using petroleum ether was applied to extract fats from small (15 g) insect samples. For preparation of larger volumes, the fats were extracted at room tem- perature in hexane. About 3 l of hexane was added to 1.5 kg of grinded insect material.