Nutritional properties of yellow mombin (Spondias mombin L.) pulp

Yellow mombin (Spondias mombin L.) is a tropical fruit with increasing acceptance in both national and international fruit markets. The aim of this work was to evaluate the centesimal composition, mineral content, total phenolics, antioxidant activity, and characterize the carotenoids of frozen yellow mombin pulp. Results indicated that the yellow mombin pulp contained an important amount of potassium and copper. The antioxidant activity and total phenolic values scored 17.5 mmol TEAC g⁻¹ and 260 mg galic acid/100 g respectively, higher than those reported for other fruits. Five carotenoids were identified, ??-cryptoxanthin, lutein, zeinoxanthin, ?? and ?? carotene, being ??-cryptoxanthin the major one, accounting for the high level of pro-vitamin A activity in the pulp. A 100 g portion of yellow mombin pulp can provide more than 37% of the recommended daily allowance of vitamin A.     

Profiling volatile compounds from Mucuna beans by solid phase microextraction and gas chromatography-high resolution time of flight mass spectrometry

Four solid phase microextraction (SPME) fibres, polydimethylsiloxane (PDMS), polydimethylsiloxane/divinylbenzene (PDMS/DVB), polyacrylate (PA), and carboxen/polydimethylsiloxane (CAR/PDMS), were evaluated for profiling of volatile compounds during cooking of Mucuna pruriens beans. A gas chromatograph coupled to a high resolution time of flight mass spectrometer system was employed for separation, detection and identification of the volatile compounds. For the first time we report a total of 26 compounds, mostly alkyl benzenes and polycyclic compounds, identified in black, white, black–white, and yellow green Mucuna beans during head space sampling employing a CAR/PDMS fibre with subsequent detection with high resolution mass spectrometry. The number of volatile compounds sampled, most notably alkylbenzenes, decreased with each hour of boiling and discarding of water extracts. As the beans approached being fully cooked, benzoic acid 2-hydroxy methyl ester was the most dominant compound in all the four types of beans. These results are a first step towards addressing some of the occupational exposure associated with cooking Mucuna beans by rural communities.     

Effect of temperature on dynamic and steady-state shear rheological properties of siriguela (Spondias purpurea L.) pulp

The present work has evaluated the dynamic and steady-state shear rheological properties of siriguela (Spondias purpurea) pulp as function of temperature (0-80 °C), as well as the applicability of the Cox-Merz rule. The product flow behavior could be well described by the Herschel-Bulkley’s model (R² > 0.98), whose parameters were modeled as function of temperature (R² > 0.91). The product has shown a weak gel behavior, with storage modulus higher than loss modulus in the evaluated frequency range. The storage and loss modules could be well described by a power function of the oscillatory frequency (R² > 0.93), whose parameters were modeled as function of temperature (R² > 0.97). Moreover, a power modified Cox-Merz rule could describe the rheological properties of S. purpurea pulp (R² > 0.96). The obtained data are potentially useful for future studies on food properties and process design.     

Chemical and sensory characterisation of aroma of Viburnum opulus fruits by solid phase microextraction-gas chromatography-olfactometry

The aroma profile of four cultivars of Viburnum opulus and one cultivar of V. opulus var. sargentii fruits was studied by solid phase microextraction of headspace volatiles and subsequent analysis by gas chromatography, mass spectrometry and olfactometry (SPME-HS-GC-MS-O). In total, 41 compounds were identified, 3-methyl-butanoic acid (63.0-71.8% of identified volatile organic compounds) being the major constituent in the three V. opulus cultivars, while 2-octanone was dominant in one cultivar of V. opulus and in V. opulus var. sargentii, amounting to 28.1% and 25.6% of identified volatile compounds, respectively. Ten odour active compounds were detected and characterised by the trained panel of judges in the course of GC-O by using detection frequency analysis (DFA). 3-Methyl-butanoic and 2-methyl-butanoic acids as well as linalool and ethyl decanoate were found to be the main odour active components for V. opulus aroma.     

Analysis of free and bound aroma compounds of pomegranate (Punica granatum L.)

Volatile aroma compounds were isolated from pomegranate arils by high vacuum distillation (HVD) and solvent extraction with diethyl ether. The HVD distillate exhibited a fresh-fruity and characteristic pomegranate aroma while the total ether extract was devoid of this note in its concentrate. Gas chromatography–mass spectroscopy (GC–MS) analysis revealed the presence of 3-octen-1-yl acetate, trans-3-hexen-1-ol, hexanol and 2-methyl pentanol only in the high vacuum distillate. Ether extract was dominated by 2-heptanol, 2-nonanol and 3-methyl-2-butanol. Based on olfactometric analysis of the HVD isolate, 3-octen-1-yl acetate was identified as the key odorant of pomegranate. Chemical synthesis of this compound, further confirmed its structure. Among the bound aroma compounds, 2-phenylethanol (40%), alpha-terpineol (4.53%) and 2-heptanol (6.35%) were identified as the major compounds existing as glycoconjugates. Identification of the character impact compound and the occurrence of glycosidic precursors in pomegranate are being reported here for the first time.     

Characterisation of fatty acids and bioactive compounds of kachnar (Bauhinia purpurea L.) seed oil

Information concerning the exact composition of kachnar (Bauhinia purpurea) seed oil is scare. In the present contribution, a combination of CC, GC, TLC and normal-phase HPLC were performed to analyse lipid classes, fatty acids and fat-soluble bioactives of kachnar seed oil. n-Hexane extract of kachnar oilseeds was found to be 17.5%. The amount of neutral lipids in the crude seed oil was the highest (ca. 99% of total lipids), followed by glycolipids and phospholipids, respectively. Linoleic, followed by palmitic, oleic and stearic, were the major fatty acids in the crude seed oil and its lipid classes. The ratio of unsaturated fatty acids to saturated fatty acid, was higher in neutral lipid classes than in the polar lipid fractions. The oil was characterised by a relatively high amount of phytosterols, wherein the sterol markers were β-sitosterol and stigmasterol. β-Tocopherol was the major tocopherol isomer with the rest being δ-tocopherol. In consideration of potential utilisation, detailed knowledge of the composition of kachnar (B. purpurea) seed oil is of major importance.     

Chemical analysis of French beans (Phaseolus vulgaris L.) by headspace solid phase microextraction (HS-SPME) and simultaneous distillation/extraction (SDE)

Headspace Solid Phase Microextraction (HS-SPME) involving divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibre and simultaneous distillation/extraction (SDE) techniques were applied to study the volatile and semi volatile compounds of thawed and cooked Phaseolus vulgaris L. A total of 104 compounds were detected by GC and GC/MS. Thereof, 76 compounds were identified for the first time in this species. The major differences between HS-SPME and SDE were found in the content of identified alcohols (23.62% SDE versus 62.20% SPME), terpenoids (39.15% SDE versus 2.45% SPME), heterocyclic compounds (13.78% SDE versus 1.21% SPME), hydrocarbons (2.22% SDE versus 13.87% SPME) and esters (0.98% SDE versus 12.98% SPME). The SPME technique was found to be useful for rapid and routine quality controls of thawed French beans, while SDE is favourable to study the entire set of flavour volatiles in the corresponding cooked samples.     

Effect of soaking and hydrothermal processing methods on the levels of antinutrients and in vitro protein digestibility of Bauhinia purpurea L. seeds

The effects of various domestic processing methods such as soaking, cooking and autoclaving on the levels of certain antinutritional factors and in vitro protein digestibility of seeds of Bauhinia purpurea L., an underutilised legume collected from South India, were investigated. The raw seeds were found to contain antinutritional factors like total free phenolics (2.75 g/100 g), tannins (2.35 g/100 g), phytic acid (692 mg/100 g) and flatulence factors, raffinose (0.54 g/100 g), stachyose (1.17 g/100 g) and verbascose (0.95 g/100 g). Soaking the seeds in distilled water caused maximum reduction in the phytic acid content (37%), whereas soaking in NaHCO₃ solution reduced significant levels of phenolics and tannins (72% and 78%, respectively). A reduction in the levels of oligosaccharides (raffinose by 63%, stachyose by 42% and verbascose by 79%) was observed during cooking. Of the attempted treatments, autoclaving appeared to be most effective in reducing levels of all the investigated antinutrients, except phytic acid, and also improved the in vitro protein digestibility of B. purpurea seeds.     

Volatile constituents of Cachucha peppers (Capsicum chinense Jacq.) grown in Cuba

The steam volatile components of three cultivars of Cachucha mature peppers (Capsicum chinense Jacq.) were isolated by steam-distillation-continuous-extraction and analysed using GC and GC-MS. The composition of volatile compounds of the peppers differs clearly for the different cultivars. The content of volatile compounds, responsible for the flavour of Cachucha peppers, varied between 110.71 and 302.53 mg kg⁻¹. One hundred and thirty-six compounds were identified, from which hexyl isopentanoate, hexyl pentanoate, hexyl 2-methylbutanoate, 3,3-dimethylcyclohexanol, γ-himachalene and germacrene D were the major ones.     

Fermentative behavior of Saccharomyces strains during microvinification of raspberry juice (Rubus idaeus L.)

Sixteen different strains of Saccharomyces cerevisiae and Saccharomyces bayanus were evaluated in the production of raspberry fruit wine. Raspberry juice sugar concentrations were adjusted to 16°Brix with a sucrose solution, and batch fermentations were performed at 22 °C. Various kinetic parameters, such as the conversion factors of the substrates into ethanol (Y_p/s), biomass (Y_x/s), glycerol (Y_g/s) and acetic acid (Y_ac/s), the volumetric productivity of ethanol (Q_p), the biomass productivity (P_x), and the fermentation efficiency (E_f) were calculated. Volatile compounds (alcohols, ethyl esters, acetates of higher alcohols and volatile fatty acids) were determined by gas chromatography (GC-FID). The highest values for the E_f, Y_p/s, Y_g/s, and Y_x/s parameters were obtained when strains commonly used in the fuel ethanol industry (S. cerevisiae PE-2, BG, SA, CAT-1, and VR-1) were used to ferment raspberry juice. S. cerevisiae strain UFLA FW 15, isolated from fruit, displayed similar results. Twenty-one volatile compounds were identified in raspberry wines. The highest concentrations of total volatile compounds were found in wines produced with S. cerevisiae strains UFLA FW 15 (87,435 μg/L), CAT-1 (80,317.01 μg/L), VR-1 (67,573.99 μg/L) and S. bayanus CBS 1505 (71,660.32 μg/L). The highest concentrations of ethyl esters were 454.33 μg/L, 440.33 μg/L and 438 μg/L for S. cerevisiae strains UFLA FW 15, VR-1 and BG, respectively. Similar to concentrations of ethyl esters, the highest concentrations of acetates (1927.67 μg/L) and higher alcohols (83,996.33 μg/L) were produced in raspberry wine from S. cerevisiae UFLA FW 15. The maximum concentration of volatile fatty acids was found in raspberry wine produced by S. cerevisiae strain VR-1. We conclude that S. cerevisiae strain UFLA FW 15 fermented raspberry juice and produced a fruit wine with low concentrations of acids and high concentrations of acetates, higher alcohols and ethyl esters.     

Flavonoids of Zizyphus jujuba L. and Zizyphus spina-christi (L.) Willd (Rhamnaceae) fruits

The ripe edible fruits of jujube, Zizyphus jujuba Miller (syn. Z. sativa Gaertner, Z. vulgaris Lam.) and Christ’s thorn jujube Zizyphus spina-christi (L.) Willd (Rhamnaceae family) were phytochemically investigated, comparing their quali-quantitative flavonoids profile. Twelve compounds from both methanol extracts have been recognized as quercetin, kaempferol, and phloretin derivatives by means of HPLC/ESI-MS analyses. Six major compounds have been purified by Sephadex LH-20 column chromatography followed by HPLC and were characterized using NMR spectroscopy. One C-glycoside, 3′,5′-di-C-β-d-glucosylphloretin, was detected in Z. spina-christi. The quantitative analysis of all compounds was also reported showing a higher content of flavonoids in Z. jujuba.     

Solid phase microextraction (SPME) applied to honey quality control

The assessment of the botanical origin of unifloral honeys is an important application in food control. The current official methods mainly use pollen analysis. The aim of this paper is to present an SPME analytical approach to the study of honey volatiles. Honey samples (40) obtained from hive sites in different regions of Italy were analysed. The samples had six different botanical origins: citrus (five), chestnut (10), eucalyptus (eight), lime tree (11), thyme (two) and dandelion (four). Melissopalynological analysis was also performed. Identification of volatile compounds was carried out by SPME/GC/MS analysis, and quantitative evaluation was done by SPME/GC/FID analysis for compounds with well‐resolved peaks. Using the SPME method, all samples with the same botanical origin gave remarkably similar GC profiles. Some volatile compounds were found only in specific floral source honey samples and thus could be interesting for use as markers. Copyright © 2003 Society of Chemical Industry     

Characterization of total capsaicinoids,colour and volatile compounds of Habanero chilli pepper (Capsicum chinense Jack.) cultivars grown in Yucatan

Total capsaicinoids, colour and volatile compounds of 10 Habanero chilli pepper (Capsicum chinense Jack.) cultivars grown in Yucatan, grouped by their colours: four red, five orange and one brown, were determined. The content of capsaicinoids, responsible for the pungency of chilli peppers, varied between 41.8 and 65.9 mg g⁻¹ dry fruit. Mean concentration of orange cultivars was 55.0 mg g⁻¹, while red cultivars had 45.0 mg g⁻¹ dry fruit, indicating that the first ones are more pungent. The composition of volatile compounds of the Habanero chilli peppers differs clearly for the different cultivars. Orange and brown cultivars have in general higher amounts of esters, with their fruity odour notes, than red cultivars. These differences are reflected in the amount of total volatiles, which is higher in orange and brown cultivars in comparison with red cultivars. From these results it can be concluded that orange and brown cultivars are better in terms of their flavour-relevant chemical composition than red cultivars.     

Effects induced by the nodulation with Bradyrhizobium japonicum on Glycine max (soybean) metabolism and antioxidant potential

This study was conducted in order to assess the effect of the inoculation of Glycine max (soybean) with Bradyrhizobium japonicum on the metabolite profile and antioxidant potential of its aerial parts. Extracts containing phenolic compounds and organic acids were analysed by HPLC–DAD and HPLC–UV, respectively. Volatiles profile was determined by HS-SPME/GC–IT-MS. The antioxidant activity of acidic and methanolic extracts was assessed against DPPH. Nodulation caused by B. japonicum led to an increase in the contents of phenolic compounds and organic acids. The same was observed for volatile compounds, with compounds like linalyl acetate, menthyl acetate and α-farnesene being detected only in inoculated plants. The phenolic extracts showed stronger antioxidant capacity than the organic acid extracts. In addition, extracts from plants nodulated with B. japonicum exhibited significantly higher antioxidant activity than control samples. These findings suggest that the inoculation with nodulating B. japonicum strains may be employed to manipulate the content of interesting metabolites in G. max aerial parts.     

Study of volatile organic acids in freeze-dried Cheonggukjang formed during fermentation using SPME and stable-isotope dilution assay (SIDA)

Volatile organic acids in freeze-dried Cheonggukjang were quantified using a stable-isotope dilution assay (SIDA) according to the fermentation period. Five organic acids, acetic acid, propanoic acid, 2-methylpropanoic acid, butanoic acid, and 3-methylbutanoic acid, were identified using solid-phase microextraction (SPME) in conjunction with gas chromatography–mass spectrometry (GC–MS). The contents of volatile organic acids in Cheonggukjang were highly dependent on the fermentation period and they increased during fermentation. Moreover, the branched-chained organic acids (namely 2-methylpropanoic acid and 3-methylbutanoic acid) were formed earlier and were present at much higher contents than the corresponding straight-chained organic acids during Cheonggukjang fermentation.     

Antioxidant activity of cichoric acid and alkamides from Echinacea purpurea, alone and in combination

The antioxidant activity of extracts of the stems, leaves, and roots of Echinacea purpurea was compared with the antioxidant activity of purified cichoric acid and alkamides, both constituents of Echinacea purpurea. The antioxidant activity was determined using different methods: effect on oxygen consumption rate of a peroxidating lipid emulsion, and scavenging of radicals, i.e. 2,2-diphenyl-1-picrylhydrazyl (DPPH), measured by two different techniques. The efficacy of the extracts in the reaction with DPPH correlated well with the amount of cichoric acid present in the various extracts. The alkamides alone showed no antioxidant activity in any of the tests. Alkamides present in the extract increased, however, the antioxidative effect of cichoric acid in the peroxidating lipid emulsion. The activity was further compared with that of rosmarinic acid, a well-characterised antioxidant, and the extracts as well as cichoric acid were found to be efficient scavengers of radicals with an activity comparable to that of rosmarinic acid. Cichoric acid was found to have a stoichiometric factor of 4.0 in scavenging DPPH and to react in a second-order reaction with DPPH with a rate constant of 40 l/mol/s at 25 °C in methanol.     

Efficacy of a volatile formulation of hydroprene (Pointsource™) to control Tribolium castaneum and Tribolium confusum (Coleoptera: Tenebrionidae)

Three- and 4-week-old Tribolium castaneum (Herbst), the red flour beetle, and Tribolium confusum (du Val), the confused flour beetle, were exposed at five different temperature-relative humidity (r.h.) combinations to a volatile formulation of the insect growth regulator (IGR) hydroprene (called Pointsource™). Typical effects associated with IGR exposure, such as arrested larval growth, morphological deformities in adults, twisted and deformed wings, and incomplete adult emergence were produced in both species. Tribolium castaneum and T. confusum were susceptible to Pointsource™, but T. castaneum appeared to be the more susceptible species. More 3-week-old larvae of both species were arrested in that stage compared to the 4-week-old larvae. Nearly all of the 3- and 4-week-old T. castaneum larvae that were able to complete development to the adult stage quickly died after they emerged and were grossly morphologically deformed. In contrast, some emerged adult T. confusum remained alive after they emerged and were not deformed in any manner or had only twisted and incomplete wings. A greater percentage of larvae of both species were arrested in the larval stage and more adults died after they emerged in exposure studies conducted at 32°C, 75% r.h. as compared with 32°C, 30% r.h., but the reverse was true for exposures conducted at 27°C. Pointsource™ appears to have excellent potential for use in controlling Tribolium species within indoor facilities.     

Changes in volatile compounds of Habanero chile pepper (Capsicum chinense Jack. cv. Habanero) at two ripening stages

The steam volatile components of Yucatan Habanero chile pepper (Capsicum chinense Jack. cv. Habanero) at two ripening stages (green and orange) were analyzed using GC and GC/MS. Both samples had several compounds in common. One hundred and two compounds were identified, from which (E)-2-hexenal, hexyl 3-methylbutanoate, (Z)-3-hexenyl 3-methylbutanoate, hexyl pentanoate, 3,3-dimethylcyclohexanol, and hexadecanoic acid were found to be the major constituents. During Habanero chile pepper maturation, the majority of volatile compounds decreased or even disappeared, some of them with green odour notes while esters, which have fruity odour notes, increased at the same time.     

Progress towards a lure to attract three stored product weevils, Sitophilus zeamais Motschulsky, S. oryzae (L.) and S. granarius (L.) (Coleoptera: Curculionidae)

The behavioural responses of Sitophilus granarius, S. oryzae and S. zeamais to synthetic 4S,5R-sitophinone alone and in combination with volatiles from kibbled carob have been investigated with a view to the development of a single lure to attract all three species. Sitophilus zeamais and S. oryzae were shown to respond to 4S,5R-sitophinone at amounts as low as 0.025 ng. Sitophilus granarius gave a significant response to 50 ng 4S,5R-sitophinone. Volatiles from kibbled carob were also shown to attract all three species. This is the first time that attraction of S. zeamais and S. oryzae to carob volatiles has been demonstrated. Fresh lures containing 4S,5R-sitophinone and carob volatiles attracted significantly more insects in pitfall bioassays for all three species than when either component was used alone. However, after 6 weeks a significant increase in response compared to the control was found only for S. oryzae and S. zeamais. The effect of insect age on response to the pheromone and carob volatiles was also studied for all three species. The response to carob volatiles decreased with increasing insect age for all three species. A significant response to 4S,5R-sitophinone was found only for 1-2-day-old adults of S. oryzae and S. zeamais but for all ages tested of S. granarius. The effect of the combination of pheromone and carob volatiles also decreased with increasing insect age.     

Volatile composition of red clover (Trifolium pratense L.) forages in Portugal: The influence of ripening stage and ensilage

The volatile organic compounds (VOCs) of three different red clover (Trifolium pratense L.) forages, fresh plant, hay and silage, were analyzed using GC and GC/MS. Comparing the volatile composition of hay and silage forages of red clover with the corresponding green plant, the effects of ripening and postharvest secondary metabolism can be noticed in hay and in ensilage. In hay, reductions of the percentages of alcohols, such as 3-methylbutanol and 1-hexanol, of aldehydes and of low boiling point ketones are observed. A sesquiterpene (β-farnesene; ca. 10%) and a phytol degradation product (6,10,14-trimethyl-2-pentadecanone; ca. 12%) were the most abundant compounds detected in hay. In silage, as a result of the fermentation of fresh red clover, esters (ca. 46%) are a more representative class of compounds.