Studies of edible Amazonian plants. Part 5: Chemical characterisation of Amazonian Endopleura uchi fruits

The chemical composition of the fruit pulp of Endopleura uchi growing in the Brazilian Amazon was investigated for characterisation and evaluation of its nutritional value. According to the analyses performed, it possesses a considerably high content of fat, characterised by a high oleic acid content. The fruit also contains remarkably high amounts of dietary fibres and phytosterols, as well as notable contents of vitamin C, vitamin E and minerals. In total, 42 volatile compounds could be identified by GC-MS in the fruit pulp aroma, which consisted mainly of the alcoholic compounds 3,3-dimethyl-2-butanol (18.8%) and eugenol (14.0%), as well as methyl and ethyl esters of fatty acids (18.5%).     

Volatile constituents of exotic fruits from Brazil

Flavor is one of the main attributes of foods and is given by a combination of volatile molecules present in the matrix. This paper reviews the general characteristics and uses and focuses on the volatile composition of selected Brazilian exotic fruits: Brazilian cherry (Eugenia uniflora), acerola (Malpighia glabra L., Malpighia punicifolia L., Malpighia emarginata DC.), jackfruit (Artocarpus heterophyllus), starfruit (Averrhoa carambola) and fruits from the genera Annona (cherimoya, soursop, sugar apple etc.) and fruits from the genera Spondias (S. purpurea, S. mombin and S. tuberosa). This is information important for flavor industry, which use different aroma compounds for the formulation of fragrances and flavorings to be used in foods, cosmetics and perfumes.     

Volatile and nonvolatile chemical composition of some date fruits (Phoenix dactylifera L.) harvested at different stages of maturity

Physico‐chemical and aroma volatile compositions of three date palm cultivars were studied throughout fruit maturation (besser, rutab and tamr stages) during 2008 harvest season. The studied parameters varied significantly through the different stages, with some variations also depending on the cultivar. Length and width of the three types of dates showed a progressive decrease during ripening. The pH level, total sugars and ash contents significantly increased up to tamr stage. Conversely, moisture, lipid and protein contents decreased. The profile of the volatile aroma compounds was evaluated using solid‐phase micro‐extraction. Sixty‐nine compounds were detected during maturation, accounting from 98.5% to 99.6% at besser, 93.1% to 99.2% at rutab and 94.3% to 98.4% at tamr stages of the total identified volatiles. The present study sheds more light on chemical characteristics of the studied cultivars that can be used in many industrial processes.     

Native carotenoids composition of some tropical fruits

Many tropical fruits can be considered a reservoir of bioactive substances with a special interest due to their possible health-promoting properties. The interest in carotenoids from a nutritional standpoint has recently greatly increased, because of their important health benefits. Here we report the native carotenoids composition in six tropical fruits from Panama, which is considered a region of great biodiversity. The native carotenoid composition was directly investigated by an HPLC-DAD-APCI-MS methodology, for the first time. In Corozo 32 different carotenoids were detected, including a high content of β-carotene and lycopene. Sastra showed the highest content of zeaxanthin among the fruit investigated. In Sapote 22 different carotenoids were detected, including β-carotene and 10 different zeaxanthin-di-esters. Frutita showed a very high content of the apo-carotenoid β-citraurin, and of a number of its esters. In Maracuyà chino 14 carotenoids were detected, including a high amounts of mono-esterified lauric acid with β-cryptoxanthin and with cryptocapsin. Mamey rojo was characterised by ketocarotenoids with κ rings, both hydroxylated and not hydroxylated.     

Volatile emerging contaminants in melon fruits,analysed by HS-SPME-GC-MS

The aim of this research was to develop and validate a headspace-solid phase micro-extraction–gas chromatography–mass spectrometry (HS-SPME–GC–MS) method for the determination of volatile emerging contaminants in fruit. The method showed good precision (RSD ≤ 14%) and satisfactory recoveries (99.1–101.7%) and LOD and LOQ values ranging between 0.011–0.033 μg kg^?1 and 0.037–0.098 μg kg^?1, respectively. The method was applied to investigate the content of volatile emerging contaminants in two varieties of melon fruit (Cucumis melo L.) cultivated adjoining high-risk areas. Glycol ethers, BHT, BHA and BTEX (benzene, toluene, ethylbenzene and xylene) were determined in melon fruit pulps for the first time, with different sensitivities depending on sample and variety. Although the amount of the volatile contaminants in the melon samples were in the order of µg kg^?1, the safety of vegetable crops cultivated near risk areas should be more widely considered. The results showed that this accurate and reproducible method can be useful for routine safety control of fruits and vegetables.     

Volatile composition of Mencı́a wines

Monovarietal Mencı́a wines from two different Appellation of Origin Controlled (AOC) of Galicia (NW Spain) were analyzed. The content of some varietal and fermentative volatile compounds was determined by gas-chromatography and GC–mass spectrometry. These red wines, independently of their origin, showed terpene profiles, that were typical of their varietal characteristics with an important contribution of linalool, citronellol, α-pinene and β-pinene. Other important varietal compounds were: norisoprenoids (α- and β-ionone, and theaspirane), phenyl-ethanol and benzyl alcohol. The 67 analytical variables were submitted to analysis of variance, and the results showed that only nine volatile compounds were significantly different (p<0.05) among the two AOC (trans-3-hexenol, 1-butanol, isobutanol, ethyl acetate, hexyl acetate, butyric acid, γ-butyrolactone, methionol, and N-(2-hydroxy-ethyl)-acetamide). Principal component analysis showed the differentiation of wines according to geographical areas.     

Free and bound flavour components of Amazonian fruits: 3-glycosidically bound components of cupuacu

The total quantity (11.7 mg/kg of pulp) of aglycones released by enzymatic hydrolysis of the glycosidic extract indicates a significant aroma potential for cupuacu. Among the 47 aglycones identified, 24 are not present in the free volatile fraction, among them, 4-methylguaiacol, 4-propylguaiacol, 2,6-dimethyl-octa-1,7-dien-3,6-diol, 2,6-dimethyl-oct-7-en-1,6-diol, homovanillic acid, 2-methyl-but-3-en-1-ol and acetic acid. The quantitatively most important aglycones are 3-methyl-butan-1-ol, 2-phenylethanol, linalol, (Z)-2,6-dimethyl-octa-2,7-dien-1,6-diol, butan-1-ol and hexan-1-ol. The methylated alditol acetates analysis of monosaccharides released by acid hydrolysis of the heterosidic extract, indicates that glucose is involved in glucosidic and glycosidic structures. Moreover, rhamnopyranose and xylopyranose units, bound in the terminal position, suggest the presence of rutinosides and small amounts of primeverosides. Six glucosides, hexyl, benzyl, 2-phenylethyl, (R) and (S)-linalyl and geranyl β- -glucopyranosides, five rutinosides, benzyl, (R) and (S)-linalyl, -terpineyl and 2-phenylethyl rutinosides and 3-methyl-but-2-enyl vicianoside were identified by GC–EIMS after TFA derivatization of the crude heterosidic fraction. Moreover, four linalol oxides, octyl, 3-methyl-butyl β- -glucopyranosides and hexyl, octyl, two linalol oxides and 3-methyl-butyl rutinosides, have been tentatively identified from their TFA mass spectra. Some glucosides are probably substituted by malonyl and unidentified acyl residues.     

Volatile sulphur compounds composition of monovarietal white wines

The sulphur compounds composition of wines produced experimentally from six white cultivars (Alvarinho, Loureiro, Trajadura, Pedernã, Azal Branco and Avesso) was evaluated during two consecutive vintages. Results show that wines could be differentiated according to their sulphur compounds content. In general, Loureiro, Trajadura and Pedernã cultivars led to wines with low concentrations of sulphur compounds; however, Loureiro wines were characterised by significant amounts of dimethyl sulphone, whereas Trajadura wines possessed a high content of 3-(methylthio)propyl acetate and 4-(methylthio)-1-butanol. Alvarinho and Avesso wines showed high levels of S-methyl thioacetate, 3-mercapto-1-propanol, 3-(ethylthio)-1-propanol and 3-methylthiopropionic acid. Significant amounts of 2-methyltetrahydrothiophen-3-one, cis- and trans-2-methyltetrahydrothiophen-3-ol were also found in Avesso wines. Azal Branco wines were low in 3-(methylthio)propyl acetate and 2-(methylthio)ethanol, and high contents in S-methyl thioacetate, 3-mercapto-1-propanol and 2-mercaptoethanol. A linear discriminant analysis of sulphur compounds levels showed a differentiation of wines according to their varietal origin.     

Organic acids and sugars composition of harvested pomegranate fruits

For two consecutive seasons, 40 Spanish pomegranate cultivars (cvs) were analysed and their individual organic acids and sugars compositions were examined. Intervarietal differences in acidity content reported by different authors were confirmed. According to organoleptic characteristics and chemical compositions three groups of varieties were established: sweet (SWV), soursweet (SSWV) and sour (SV). On average, for two seasons, total organic acids on a dry basis ranged between 0.317 g/100 g (SWV) and 2.725 g/100 g (SV). Citric, malic, oxalic, acetic (first reported here), fumaric, tartaric and lactic acids were detected, although lactic and fumaric were not quantifiable. On average, for both seasons, citric acid was predominant with a range of 0.142–2.317 g/100 g (average content for all CVS, 0.282 g/100 g). Malic acid was the second most abundant, with a range of 0.135–0.176 g/100 g (average of 0.139 g/100 g). Total sugars ranged between 11.43 g/100 g and 13.5 g/100 g. Glucose, fructose, sucrose and maltose were detected, although maltose (first reported here) was not quantifiable. Fructose ranged between 5.96 g/100 g and 7.04 g/100 g, with an average of 6.58 g/100 g, quite similar to that of glucose (6.14 g/100 g). Sour cv showed the lowest fructose and glucose contents. The average sucrose content was 0.01 g/100 g. Other differences among the groups of cvs were detected. Low total sugars and high acids were found in SV. The SSWV group had higher sugars than the SV. However, no difference in total sugars between SSWV and SWV was found. A lower acids content than SV but higher than SWV was found in the SSWV group. No other studies have been published so far on the individual organic acids and sugars of pomegranate fruit. Received: 27 July 1999 / Revised version: 28 September 1999     

Volatile constituents of unripe and ripe kundang fruits (Bouea macrophylla Griffith)

Kundang, a seasonal, tropical fruit is consumed either as raw (unripe) or ripe in south-east Asia. Investigations performed by using gas chromatography-mass spectrometry revealed volatile constituent compounds in ripe fruits to be much higher than unripe fruits. Nearly 82 compounds (comprising 99.96% of the total volatiles) and 121 compounds (encompassing 97.33% of the total volatiles) were identified in unripe and ripe fruits, respectively. Results generated is envisaged to enhance the existing database on tropical fruits volatile profiles, as well as benefit local food industries (to exploit the unique fragrance character impact compounds for aroma essence production) for commercial usage.     

Volatile profile of Arbutus unedo L. fruits through ripening stage

Arbutus unedo L. is a Mediterranean shrub used in the production of jams, marmalades and beverages, as well as in traditional medicine. In this work, the effect of ripening on the volatile compounds of the fruits of A. unedo was evaluated, using headspace-solid phase microextraction combined with gas chromatography/ion trap-mass spectrometry. Alcohols are the main component of the volatile fraction of A. unedo fruits, followed by aldehydes and esters. The main volatile compounds identified were (Z)-3-hexen-1-ol, 1-hexanol, hexanal, (E)-2-hexenal and hexyl acetate, all formed through the lipoxygenase pathway (LOX). The green odours are progressively replaced during ripening by floral and sweet sensations, due to the decrease in alcohols, aldehydes and esters, resulting in the unmasking of the aromas associated with the minor compounds (mainly monoterpenes and norisoprenoid compounds) that compose A. unedo fruits.     

Volatile composition of raw spirits of different botanical origin

The main purpose of the research was to determine the volatile composition of raw spirits, on the basis of trace compound isolation from their volatile fraction, as well as a comparison of the obtained volatile profiles of agricultural distillates of different botanical origins (maize, wheat, triticale, rye). This approach was chosen to improve methods of quality control and quality assurance in the spirit industry. Volatile composition of all raw spirit samples derived from different raw materials (rye, triticale, maize and wheat) were formed using headspace solid‐phase microextraction (HS‐SPME) and capillary gas chromatography–mass spectrometry (GC‐MS). Performed studies indicated the presence of over 100 compounds in the raw spirit volatile fraction. The richest volatile profile was obtained from samples produced from wheat and the poorest from those produced from corn. Moreover, on the basis of performed discriminant analysis (using the variables 2‐methylbutanol + 3‐methylbutanol, 3‐methylbutyl hexanoate, ethyl dodecanoate, ethyl heptanoate and 3‐methylbutyl octanoate), it was possible to distinguish between agricultural distillates originating from triticale and distillates produced from wheat. Copyright © 2013 The Institute of Brewing & Distilling     

Chemical composition and proposed use of two semi-wild tropical fruits

The edible fruits of two native species of Southeast Asia, Baccaurea sapida (Roxb.) Muell. Arg. and Flacourtia jangomas (Lour.) Raeusch, were analyzed for sugars, amino acids and minerals. The values obtained (B. sapida and F. jangomas, based on dry weight) are: protein 5·5, 3·9%; vitamin C 178, 218 mg/100 g; fructose, α- and β-glucose and sucrose 21%, 21% total; Ca 169, 175; K 137, 158; P177, 147; Fe 100, 118; Mg 105, 57 mg/100 g. Concentrations of amino acids, Na, Mn, Cu and Zn are also reported. These fruits would be useful as supplements to a balanced diet.     

Two exotic fruits positively affect rat’s plasma composition

The aim of this investigation was to determine the bioactive compounds and the antioxidant potentials of Snake fruit and Mangosteen and their influence on plasma lipid levels and antioxidant activity in rats fed cholesterol-containing diets. It was found that total polyphenols and antioxidant potentials of Snake fruit were significantly higher than those of Mangosteen (P < 0.05). A cholesterol-containing diet supplemented with the studied exotic fruits showed a positive affect on rat’s plasma lipid levels and on the antioxidant activity during 30 days of feeding. In rat’s plasma of the Chol/Snake diet group, the fibrinogen fraction showed a decrease in the amounts and compositions of electrophoretic protein bands in the range of 110 and 14 kDa. However, all the positive results of this experiment on animals could not be automatically applied to humans.     

Identification of bioactive composition and antioxidant activity in young mandarin fruits

The naturally dropped fruits of nine mandarin cultivars were collected and evaluated for their potential use in traditional Chinese medicine (TCM) or as nutraceutical materials. The main bioactive substances were analysed, including four flavanone glycosides (narirutin, naringin, hesperidin, and neohesperidin), two polymethoxlated flavones (nobiletin and tangeretin), and another two compounds of limonoid, and synephrine. The total phenolic content (TPC) and antioxidant capacity were determined by Folin–Ciocalteu, FRAP, DPPH, and ABTS assays. Hesperidin and narirutin were the main flavanones in all tested cultivars. Naringin and neohesperidin were not detected in any of the mandarin cultivars except for Ougan, which contained 10.6 ± 0.6 mg/g naringin. The highest contents of nobiletin and tangeretin were found in Zhuhong (13.7 ± 0.4 and 12 ± 0.2 mg/g, respectively), and in Ougan (11.6 ± 0.1, 10.3 ± 0.1 mg/g, respectively). High synephrine levels were found in Zhuhong (22.5 ± 1.4 mg/g) and Manju (17.6 ± 0.3 mg/g). The limonoid content varied from 104.54 to 1128.13 μg/g with the highest amounts in Manju. The extractable phenolic acids (free and ester form) were more prevalent than the bound forms. Ferulic and caffeic acids were predominate in both the extractable and bound phenolics. The TPC were in order from high to low: Zhuhong > Bendizao Wenzhang Satuma > Ponkan > Manju > Ougan > Shantian Satuma > Gongchuan Satuma > Rinan No. 1 Satuma. The antioxidant capacity followed a very similar trend when assayed by the FRAP, DPPH, and ABTS procedures. The results showed that the dropped fruit from super early to medium mature Satsuma, a world famous mandarin variety, contained relatively lower bioactive substances than the other local varieties. The results also suggest that the dropped mandarin fruit, especially the local varieties such as Zhuhong, Bendizao, Ougan, Manju, and Ponkan, could serve as a good source of extractable nutraceuticals and to serve as a raw material source for crude TCM.     

Volatile and carbohydrate composition of rare unifloral honeys from Spain

Volatile composition and carbohydrate content of Spanish honey samples from uncommon botanical origins have been studied by gas chromatography coupled to mass spectrometry. About 100 volatile compounds were identified; some of them appeared to be characteristic of particular honey types, such as methyl salycilate in willow (Salix spp.), 2,6,6-trimethyl-2,4-cycloheptadien-1-one (eucarvone) in almond tree (Prunus dulcis) and isophorone in strawberry-tree (Arbutus unedo). Concentration ranges for major carbohydrates were similar to those previously reported in other honeys with different botanical origins, although concentrations of maltulose in avocado honeys (Persea americana) and of melezitose in Quercus ilex honeys were higher. Some carbohydrate alcohols could also be considered as markers of honey botanical origin, such as quercitol for Q. ilex and perseitol for avocado.