Detecting seed oils

presence of lauric acid oil babassu, coconut, palm kernel 

presence of stearic acid 5% peanut, soyabean, sunflower 

presence of oleic acid 55% babassu, coconut, cottonseed, grapeseed, maize, palm kernel, safflower 

---

The paper by Flor el al. (1993) was probably a stimulus for the official method in the EEC regulation 2568/91 for detecting seed oil sophistication of olive oil, defining the difference as ECN42 HPLC — ECN42. 

Thev have detected ihr following bodies in the oil /-Imalol, f-ter-pliieol, uecol, aud gei aniol. They consider lhal this de tio-rotatory seed oil Is present iu the dexlro-rotiitory linnloe oils of commerce above re-... 

It is impossible to reveal the botanical species from which the seed oil used in the examined lamps was actually produced, e.g. to say whether the oil came from radish as reported by Pliny or from another Brassicaceae plant such as rapeseed. However, the detection of the characteristic markers in lamps from Antinoe, one of the main urban centres of Roman Egypt, represents a chemical confirmation of the widespread use of cmciferous oil at that time, and is consistent with ancient documents [61,62]. This identification is... 

Fig. 29 Separation of triacylglycerols from sunflower seed oil by HPLC with a silver ion column and mass detection. For conditions see text. S = saturated fatty acid M = monounsaturated fatty acid D = di-unsaturated fatty acid.

AJ Speek, J Schrijver, WHP Schreurs. Vitamin E composition of some seed oils as determined by high-performance liquid chromatography with fluorometric detection. J Food Sci 50 121-124,1985. 

These trans compounds have different physical properties than natural cis isomers and are readily separated with gas chromatography analysis. The detection of trans isomer fatty acids in an olive oil indicates addition of seed oils to olive oil, of refined olive oil to virgin olive oil and of esterified oil to residue olive oil and olive oil. 

High performance liquid chromatography criteria for detecting sophistication with seed oils... 

This finding may represent a useful element for the further improvement of this analytical method, which would possibly permit the detection of olive oil sophistication with seed oils. 

The major conceptual limitation of all regression techniques is that one can only ascertain relationships, but one can never be sure about underlying causal mechanism. The explanation of conclusions with the assistance of other sciences would avoid reaching nonsense conclusions. A hypothetical paradigm can be to use the electronic nose for detecting the adulteration of refined olive oil with refined seed oils when these kinds of oils do not contain volatiles (refined process of vegetable oils includes the deodorization). 

The only conjugated dienoic fatty acid isolated from plant sources (the seed oil of Chilopsis linearis) is reported to be trans-lO, trans-12-octadecadienoic acid. In contrast, fatty acids with conjugated triene systems have been detected in various plant species. Tung oil is the commercial source of the most widespread fatty acid from this group, 9-cis, W-trans, I i-trans-octadecatrienoic (a-eleostearic) acid (1, 2). 

Olive oil contains a-tocopherol in the range of 12-190 mg/kg. According to one report (43), olive oil tocopherols were found to consist of 88.5% a-tocopherol, 9.9% (3--f y-tocopherol, and 1.6% 8-tocopherol. Tocopherol content can be used to detect adulteration of olive oil with seed oils. 

Differentiation Between Virgin and Refined Oiive Oil and Detection of Refined Olive Oil and Seed Oils in Virgin Olive Oil... 

Red raspberry seed oils, extracted by either hexane (2) or cold-pressing (3), were examined for their fatty acid compositions. Both methods detected very similar... 

Black raspberry, Red raspberry, Boysenberry, Marionberry Blueberry, Cranberry, Buckthorn sinesis, Buckthorn rhamnoides, and Buckthorn mongolica, stand for black raspberry red raspberry, boysenberry, marionberry, blueberry, cranberry, buckthorn sinesis, buckthorn rhamnoides, and buckthorn mongolica seed oil, respectively. Numbers correspond to the references cited, nd stands for not detected. 

Recent investigations of hemp seed oil (5, 11, 12) reported similar findings in fatty acid compositions. The n-3 fatty acid, a-linolenic acid, was determined to constitute between 15.1% and 19.4% of total fat (Table 2). Gamma-linolenic acid (18 3n-6) was also detected in two of the studies, and comprised up to 3.6% of total fatty acids (11, 12) (Table 2). The most prevalent fatty acid was linoleic in all of the studies, which was between 53.4% and 60.0% of total fatty acids and was followed by a-linolenic, oleic, palmitic, y-linolenic, and stearic acids. Eicosadienoic, arachi-dic (20 0), and behenic (22 0) acids were also detected in small quantities. 

Melon, Cucumis melo, is a member of the Cucurbitaceae family and grows best in tropical regions. The pulp of the fruit has pleasant flavor and taste, and the seeds are generally treated as waste however, medicinal effects have been reported for the seeds (24, 25). Hexane-extracted seed oil of Cucumis melo hybrid AF-522 was determined to contain 64 g of linoleic acid per 100 g of total fatty acids (Table 4) (24). Significant amounts of oleic, palmitic, and stearic acids were also detected in the melon seed oil. The specific gravity (28°C), refractive index (28°C), and iodine value of the seed oil were 0.9000, 1.4820, and 112, respectively, under the experimental conditions (24). Earlier in 1986, Lazos (25) extracted the oil from Cucumis melo seeds and examined its physicochemical properties (25). Linoleic acid was the primary fatty acid and accounted for 64.6% of the total fat (w/w), along with 20.1% oleic acid, and 14.7% total saturated fatty acids (Table 4). Iodine value and refractive index (40°) of the seed oil were 124.5 and 1.4662, respectively. 

Rose, Rosa canina L., also known as dogberry or hop fruit, is in the Rosaceae family. The fruit of this particular species of rose is generally used to prepare a stew. The seeds from Rosa canina L. were investigated for their chemical composition and nutritional values for medicinal purposes. Seed oils were prepared from fruits grown at three locations in Turkey and evaluated for their fatty acid composition (31). Linoleic acid was the primary fatty acid detected, which ranged from 48.6-54.4% of total fatty acids, followed by a-linolenic acid (16.4-18.4%) and oleic acid (14.7-18.4%) (Table 4). The seed oil contained approximately 85% total unsaturated fatty acids, indicating that Rosa canina L. seed oil may be an excellent source for unsaturated and essential fatty acids. 

Granny Smith, Sturmer, Dougherty, and Golden Delicious stand for seed oil of four varieties of apple. Numbers correspond to the references cited, nd stands for not detected. 

The cherry tree Prunus avium L.) is a member of the Rosaceae family. Cherry seed contains about 18% oil on a dry weight basis (48). Significant levels of oleic acid were detected in the cherry seed oils prepared by hexane extraction using a Soxhlet apparatus. Oleic acid comprised 24—38% of the total fatty acids from three different varieties of cherry fruits (Table 7) (48). Linoleic acid was the major fatty acid in the cherry seed oil, and ranged 40 9% in the seed oil, along with ot-eleostearic (18 n-5), palmitic, stearic, arachidonic, and ot-linolenic acids (Table 7). alpha-eleostearic acid comprising 10-13% of cherry seed oil, is a conjugated... 

The fluted pumpkin Telfaria occidentalis) is a tropical gourd native to West Africa. It is taxonomicafly classified as a member of the Curcubitaceae family. The fruits are very large and weigh up to 13 kg, but only the seeds are edible (33). The seeds are very rich in both protein and fat, containing approximately 28% and 55%, respectively, from whole oven-dried fluted pumpkin seeds (26). The fatty acid profile of fluted pumpkin seeds demonstrated a high oleic acid content of 35.4% and a total saturated fatty acid concentration over 34% (Table 7) (26). Significant level of linoleic acid (18 2n-6) was also detected in the seed oil. 

---