CHEMICAL COMPOSITION OF OIL FROM TETRACARPIDIUM CONOPHORUM ((MÜLL. ARG.) HUTCH. AND DALZ.) NUTS

Tetracarpidium conophorum is known in the littoral and the western Cameroon as kaso or ngak and serves as an edible nut eaten between meals. The physicochemical characteristics, the fatty acids and the triacylglycerols (TG) of T. conophorum nut oil (Type 1 and Type 2) from the southern continental low lands were studied. The oil content varied between 55.75 and 61.62%. The iodine value (180–182), saponification value (175–176) and nitrogen (8.08–8.78) were similar. Ashes varied between 8.40 and 9.68%. The main fatty acid of the golden yellow was linolenic acid (69.47–70.39%) as determined by capillary gas chromatographic analysis. The triacylglycerol profil obtained by reversed phase liquid chromatography showed 10 TG with three major ones identified as     

CHEMICAL PROPERTIES OF RICINODENDRON HEUDELOTII (BAIL.) SEED OIL

The technological characteristics and the fatty acid composition of Ricinodendron heudelotii (Bail.) seed oil from two different regions of Cameroon were studied. The fatty acid composition was determined by gas chromatography on a capillary column. The oil content varied according to the region (44.9–54.7%). The iodine value (160), saponification value (190) and unsaponifiable matter content (1.6%) were similar for the two types of seeds examined. The oil was composed mainly of linoleic acid (25–30%) and a polyunsaturated fatty acid (PUFA) found to be α-elaeostearic acid (48–56%). The latter fatty acid is subject to transformation during the esterification processes due to its trienic conjugated bonds. The triacylglycerol profile obtained by reversed phase liquid chromatography showed 20 triacylglycerols with two major ones identified as linoleodi-α-elaeostearic (29.7–33.1%) and tri-α-elaeostearic (13.1–15.9%).     

COMPARISON OF CHEMICAL COMPOSITION AND ANTIOXIDANT ACTIVITY OF GLYCOSIDICALLY BOUND AND FREE VOLATILES FROM CLOVE (EUGENIA CARYOPHYLLATA THUNB.)

The present article reports on the chemical composition and antioxidant activity of clove glycosidically bound volatile compounds in comparison with their essential oil. The comparison of chemical composition of volatile aglycones with the chemical composition of essential oil revealed only eugenol as identical. To measure the antioxidative activity of the clove enzymatically released aglycones and its essential oil, two different assays were performed: the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging method and the ferric reducing/antioxidant power (FRAP) assay. Both methods showed that the clove volatile aglycones possess lower antioxidant properties than its essential oil. The volatile aglycones radical-scavenging activity measured by DPPH method was lower than butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) activity. The reducing capacity measured by FRAP method for volatile aglycones was lower than BHA capacity and higher than BHT capacity. Some differences in activity obtained by two methods could be explained with different solvent polarity.

PRACTICAL APPLICATIONS

Many secondary metabolites are glycosylated and accumulate as nonvolatile glycosides. Since the glycosides are able to release their aglycones by enzymatic hydrolysis, these compounds could be considered as possible precursors of antioxidant substances in plant. They may contribute to the total antioxidant activity of plant and could be used as natural antioxidants.     

CHEMICAL COMPOSITION AND ANTIOXIDANT ACTIVITY OF SAPOTA (ACHRAS SAPOTA LINN.) FRUIT

Sapota (Achras sapota Linn.) belongs to the family Sapotaceae and is assigned for various properties in the traditional system of Indian medicine. For the first time, nutritional quality and antioxidant activity of sapota juice with reference to its chemical composition have been investigated employing various well‐established in vitro methods. Chemical composition analysis of sapota juice revealed that it is one of the rich sources of sugars, proteins, ascorbic acid, phenolics, carotenoids and minerals like iron, copper, zinc, calcium and potassium. Apart from the nutritional components just given, sapota juice showed potential antioxidant activity against 1,1‐diphenyl‐2‐picrylhydrazyl free radicals and superoxide radicals. Sapota juice potentially inhibited the free radical‐mediated lipid peroxidation in a liposome model system. Total reducing‐power assay revealed the potential reducing power of sapota juice. The multiple radical‐scavenging potential of sapota juice was found to be due to its nutraceutical components, viz., phenolics, carotenoids and ascorbic acid.     

EFFECT OF PROCESSING ON SOME CHEMICAL CONSTITUENTS OF PISTACHIO NUTS

The effect of processing on changes in fatty acids, sugars and amino acids in pistaschio nuts during blanching, drying and roasting was monitored. Blanching in hot water led to some loss in fatty acids, sugars and amino acids. Roasting further decreased the availability of the constituents. The magnitude of loss of the constituents was in the following order: blanching > roasting > drying. The composition profile of each of the constituents was analyzed. There was variation in the distribution of fatty acids among the raw and processed nuts. Unsaturated fatty acids were more susceptible to changes during processing. The combined loss of oleic and linoleic acids amounted to 22.29% of that present in the raw nuts. Fructose, glucose, sucrose and raffinose were shown to be present in the nuts. The loss of sucrose was higher than the monosaccharides during processing. Glutamic acid, leucine, proline 56.50% of the amino acids present, and blanching, drying and roasting successively caused losses in the availability of these amino acids. The effect of processing on nutritional values has been a subject of concern to consumers and food processors. The present investigation reveals that the loss in various components in the nuts deserves more attention.     

抽油烟机回收油的脂肪酸组成变化特征研究

食用油在烹饪过程中挥发,会在抽油烟机系统中凝结。分别以花生油、葵花籽油、茶籽油、玉米油和调和油5种不同植物油为食用油进行烹饪试验,收集经抽油烟机系统凝结的油脂。通过测定抽油烟机回收油和相应未烹饪油的脂肪酸,来分析回收油脂肪酸组成变化特征。结果表明,回收油的脂肪酸种类和含量显著性差别于未烹饪油(P0.05)。回收油增加了C14∶0、C16∶1n7c短碳链脂肪酸,其饱和脂肪酸的含量增加了,不饱和脂肪酸含量减少了,其脂肪酸不饱和度明显降低,仅是未烹饪油的50%~61%。回收油中短碳链脂肪酸有增加的趋势,长碳链脂肪酸含量有减少的趋势,而且新增了食用油本底很少或没有的C18∶3n3c和EPA脂肪酸。回收油的品质也开始变化,有些回收油的脂肪酸已严重偏离了正常植物油的特征值。因此,抽油烟机回收油已不适合再食用,烹饪过程中应降低烹饪温度以减少食用油的变质。     

CHEMICAL COMPOSITION AND ANTIMICROBIAL PROPERTIES OF THE ESSENTIAL OIL OF ORIGANUM SACCATUM L.

The chemical constituents of essential oil isolated by hydrodistillation of aerial parts of Origanum saccatum L. growing wild of 39 constituents were identified accounting for 99.11% of the oil of O. saccatum. The oil of O. saccatum contained, as main components, p -cymene (82.8%), γ-terpinene (6.2%), p -cymene-8-ol (1.5%) and carvacrol (1.2%). The essential oil of O. saccatum was characterized by its high content of p -cymene.
Preliminary experiment was carried out in vitro using the diffusion method to investigate antimicrobial activity of the O. saccatum oil. The oil exerted varying levels of antimicrobial effects on the growth of all microorganisms (except for 100 ppm which belongs to Bacillus subtilis, Bacillus aureus ). The antimicrobial activity of the O. saccatum oil was established by using agar diffusion method. The results showed that antimicrobial activity increased depending on the concentration degree used. The highest sensitive bacteria had Staphylococcus aureus and Escherichia coli. As a result, inhibitory effect of oil was weak on tested bacteria compared with fungi. The extent of inhibition of tested microorganism growth was dependent on the concentrations of essential oil used.

PRACTICAL APPLICATIONS

Some investigations showed that the use of spices in place of chemicals and synthetics has become indispensable because of their antimicrobial effects and also because of the increasing risk of the side effects of chemical and synthetic preservatives on health. Also, spices and derivatives have been used since ancient times to preserve foods, make foods tastier, cure diseases and produce aromatic substances. Many species of aromatic plants belonging to the Labiatae family grow wild in the east Mediterranean basin. Dried oregano leaves are well known not only in the herb industry mainly but also for other appetizing applications, and as a source of essential oils     

COMPOSITION OF CROCINS AND PICROCROCIN FROM SPANISH SAFFRON (CROCUS SATIVUS L.)

A method for simultaneous identification and quantification of crocins and picrocrocin by HPLC-DAD in aqueous extracts of saffron spice was used. The coefficients of variation obtained were lower than 10% for a majority of the crocins and picrocrocin. These substances are not found as standard compounds, for this reason it was necessary to obtain the response factor for each compound by collecting the fractions of each chromatographic peak and by using molar absorpitivity. This method can be used not only for crocins and picrocrocin determination but also for adulteration detection of saffron with water-soluble colorants. The method was applied to 260 samples of Spanish saffron, which came from the regions where saffron is an important crop, i. e., Castilla-La Mancha and Aragón. Spain is in the top group of saffron producers and Castilla-La Mancha is the largest saffron producing region in Spain. Four crocins and picrocrocin were ranked and the values used for differentiation according to origin. Only discriminant analysis could explain 100% of the variance by samples and location. The major discriminant variable was trans-crocin 4.     

VARIATIONS IN ESSENTIAL OIL COMPOSITION DURING MATURATION OF CORIANDER (CORIANDRUM SATIVUM L.) FRUITS

The composition of volatile components of the essential oils extracted from fruits of coriander ( Coriandrum sativum L.) at four stages of maturity was studied by gas chromatography–flame ionization detector and gas chromatography-mass spectrometry. Essential oil yields showed marked increase during maturation process and 41 compounds were identified. Linalool was the main compound in all ripening stage amounting from 36.69 to 72.35%. Geranyl acetate (35.17%), β-caryophyllene (3.47%) and borneol (3.26%) were the main compounds at the first stage of maturity (immature fruits). At the second stage, geranyl acetate (8.21%), camphor (4.01%) and menthol (2.96%) were reported as the main constituents. In the third stage, geranyl acetate (20.66%), α-humulene (5.44%) and limonene (1.68%) were the main compounds. At the final stage of maturity (mature fruits), essential oil consist mainly on geranyl acetate (1.49%) and borneol (0.97%) in addition to linalool (72.35%). Additionally, accumulation of monoterpene alcohols was observed during maturation process of coriander fruit.

PRACTICAL APPLICATIONS

The chemical composition of the essential oil of coriander ( Coriandrum sativum L.) fruits is characterized by the occurrence of numerous components with great economical values. The oxygenated monoterpene and linalool were the most used ingredient in the cosmetic, perfume and food industries. On the other hand, the increasing market demands of the oxygenated components, widely present in this oil make it in the first rank of natural product. The formers were only obtained from the mature fruits. In this context, knowledge of their evolution during maturation process of the fruits seems to be a helpful tool for a better use of this economical potential.     

INTERFERENCE OF CARBOHYDRATES DURING PURIFICATION OF PEROXIDASE FROM PALM (EUTERPE EDULIS MART.)*

Palmito (Euterpe edulis Mart.) peroxidase was initially prepared as an acetone powder to eliminate phenols and lipids. A 30–80% (NH₄)₂SO₄ fraction was used to characterize some biochemical properties of this enzyme. The main interference during enzyme purification was found to be the interaction of acid carbohydrates with peroxidase. The optimum condition to eliminate this interference was found to be extraction at pH 4.0, which preferentially extracts most of the carbohydrates but not the enzyme. CaCl₂ was found to be a compound which selectively precipitates with acid carbohydrates and proteins and increased peroxidase activity. Gel isoelectrofocusing was used to study the interaction between the acid polymers and the proteins. The pH optimum of the enzyme was found to be around 4.0. The molecular weight of the enzyme was estimated to be 40,000. The Km of peroxidase with H₂O₂ was 2times10⁻³M and with guaiacol, 4.8 times 10⁻³M. NaCl, NaF and NaN₃ were found to inhibit peroxidase as a function of pH; as the pH decreased, the inhibition increased.