Article

Characterisation of calamansi (Citrus microcarpa). Part I: Volatiles, aromatic profiles and phenolic acids in the peel

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Cuevas-Glory et al [7] identified 59 and 72 compounds in the peel and leaf oils of calamondin, respectively, and found limonene was the most prominent compound that accounted for 77.0% of peel oil. Cheong et al [8] identified a total of 79 volatile components of calamansi peel from Vietnam, the Philippines, and Malaysia. Moreover, they reported that Malaysian calamansi peel has a statistically higher percentage of methyl N-methylanthranilate than calamansi peel from other areas. ...
... Umano et al [14] found that the yields of Japanese kumquat essential oil obtained by SD and solid phase extraction are 0.011% and 0.019%, respectively. Cheong et al [8] reported that the yield of volatiles obtained in hexane peel extracts is relatively higher than those in dichloromethane peel extracts. In the present study, we found that the yield of essential oils obtained by cold pressing (CP) from calamondin peel is relatively low. ...
... Takeuchi et al [6] identified that the major component of calamondin peel extracted with hexane is limonene and the second major compounds are g-terpinene and b-elemene. In addition, Cheong et al [8] determined that the major constituents of calamondin peel isolated with hexane are limonene and b-myrcene, and the second major compounds are b-pinene, linalool, and a-pinene. ...
Article
Volatile constituents of calamondin peel or whole fruit were obtained by cold pressing, steam distillation, or hot water treatment at 90°C for 15 minutes followed by steam distillation. The volatile components of the essential oils were identified by direct injection coupled with gas chromatography–flame ionization detector. A total of 54 compounds were identified, including 13 monoterpenes, 7 monoterpene alcohols, 1 monoterpene oxide, 4 monoterpene aldehydes, 2 monoterpene ketones, 4 monoterpene esters, 12 sesquiterpenes, 3 aliphatic alcohols, 6 aliphatic aldehydes, and 2 aliphatic esters, with limonene and β-myrcene as the major compounds. The results showed that hot water treatment increased the yields of essential oils from both peel and whole fruit. The relative percentage of the principle constituents in the various prepared essential oils were similar, except for some minor compounds, including linalool, terpinen-4-ol, α-terpineol, and carvone, the content of which were boosted by steam distillation. Whole fruit contained higher levels of monoterpene alcohols than peel did.
... Very few studies were conducted investigating the phenolic compounds of calamondin. Four phenolic acids, including caffeic acid, p-coumaric acid, ferulic acid, and j o u r n a l o f f o o d a n d d r u g a n a l y s i s x x x ( 2 0 1 6 ) 1 e1 4 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 sinapic acid, were determined in the peel [83] and juice [84] of calamondin. They exist in both free and bound form. ...
... The total phenolic contents of calamondin peel extracts were higher than those of pulp extracts [85,86]; the levels of phenolic acid also showed similar phenomena [83,84]. The content of phenolic compounds in peel was 1054e1894 mg/ 100 g dry extract, which was higher than that in pulp (189e1053 mg/100 g dry extract). ...
Article
Full-text available
Kumquat and calamondin are two small-size citrus fruits. Owing to their health benefits, they are traditionally used as folk medicine in Asian countries. However, the research on flavonoids and biological activities of kumquat and calamondin have received less attention. This review summarizes the reported quantitative and qualitative data of phenolic compositions in these two fruits. Effects of maturity, harvest time, various solvent extractions and heat treatment of phenolic compositions, and bioactivities were discussed; distributions of the forms of phenolic compounds existing in kumquat and calamondin were also summarized. Furthermore, biological activities, including antioxidant, antityrosinase, antimicrobial, antitumor, and antimetabolic disorder effects, have also been discussed. Effective phenolic components were proposed for a certain bioactivity. It was found that C-glycoside flavonoids are dominant phenolic compounds in kumquat and calamondin, unlike in other citrus fruits. Up to now, biological activities and chemical characteristics of C-glycoside flavonoids in kumquat and calamondin are largely unknown.
... A study done on adding calamansi lime in sugarcane juice showed a significantly increased antioxidant activity and reduced microbial count in the juice [7]. The results may be caused by the presence of phenolic compounds present in calamansi lime such as caffeic, p-coumaric acid, ferulic acid and sinapic acid that function as natural antioxidants and antimicrobial agents [8]. This implies that a combination of calamansi lime which contains several types of acids with chili bird paste could be a potential marinating paste for other types of protein food. ...
... From Table 3, paste C which contains calamansi lime and stored at 4 °C showed significantly the slowest microbial growth. The preservative effect of calamansi lime which contains organic acid, citric acid and malic acid may delay the bacterial growth [8]. Citric acid can be considered as an acidulant, a substance that limits or inhibits microbial proliferation [19]. ...
Article
Full-text available
This study addresses the utilization of calamansi lime as a natural preservative in extending the shelf life of underutilized local chili bird paste. Chili bird and calamansi lime are usually harvested in large amounts but their rapid deterioration limits their functions thus processing method is essential to compensate their short shelf life. In the study, chili bird is processed into paste and added with calamansi lime as a preservative agent. The effect of calamansi lime on the paste is evaluated through the paste stability, stored for 12 days at different temperatures (37 °C and 4 °C). The paste functionality was assessed by its effect on chicken fillet as marinating paste. The paste containing calamansi lime stored at 4 °C (paste C) showed the best results by having the lowest microbial growth (5 log CFU/mL), a high DPPH-radical scavenging activity (57.4%) and low pungency index (0.513). The combination of phenolic compounds found in chili paste and calamansi lime contributes to antimicrobial and antioxidative activity. The addition of calamansi lime significantly helps in maintaining the red color of paste C with only 17% color reduction occurred during 12 days of storage. The organic acid found in calamansi lime also helps in regulating the paste C pH at 3.98 and acid titratability of 1.44%. The chili paste C showed significant tenderizing effect as chicken fillet marinade with shear force value of 0.53 lbs. The chili bird paste containing calamansi lime could be a potential marinade product that promotes a green and cheap food practice.
... However, when the oil fraction increased to 40%, WPI stabilized emulsions could not further get refined in DMTS after three cycles what resulted in higher values of d 3,2 and span than those obtained with BSFPC stabilized emulsions, which could be successfully refined over five emulsification cycles (Figure 6f). The poor performance of WPI as an emulsifier in the LO/W system could be linked to the chemical composition of LO, containing anhydrous acids and phenolic acids from the peel [58,59], able to diffuse in the water phase and reduce pH below the WPI isoelectric point, in a range of 4.8-5.1. The water phase of LO/W emulsions containing 40% oil fraction showed a pH of 5.03 that may cause aggregation and precipitation of whey proteins and, in turn, a reduction of their surface-active capacity. ...
... However, when the oil fraction increased to 40%, WPI stabilized emulsions could not further get refined in DMTS after three cycles what resulted in higher values of d3,2 and span than those obtained with BSFPC stabilized emulsions, which could be successfully refined over five emulsification cycles (Figure 6f). The poor performance of WPI as an emulsifier in the LO/W system could be linked to the chemical composition of LO, containing anhydrous acids and phenolic acids from the peel [58,59], able to diffuse in the water phase and reduce pH below the WPI isoelectric point, in a range of 4.8-5.1. The water phase of LO/W emulsions containing 40% oil fraction showed a pH of 5.03 that may cause aggregation and precipitation of whey proteins and, in turn, a reduction of their surface-active capacity. ...
Article
Full-text available
There is a pressing need to extend the knowledge on the properties of insect protein fractions to boost their use in the food industry. In this study several techno-functional properties of a black soldier fly (Hermetia illucens) protein concentrate (BSFPC) obtained by solubilization and precipitation at pH 4.0–4.3 were investigated and compared with whey protein isolate (WPI), a conventional dairy protein used to stabilize food emulsions. The extraction method applied resulted in a BSFPC with a protein content of 62.44% (Kp factor 5.36) that exhibited comparable or higher values of emulsifying activity and foamability than WPI for the same concentrations, hence, showing the potential for emulsion and foam stabilization. As for the emulsifying properties, the BSFPC (1% and 2%) showed the capacity to stabilize sunflower and lemon oil-in-water emulsions (20%, 30%, and 40% oil fraction) produced by dynamic membranes of tunable pore size (DMTS). It was proved that BSFPC stabilizes sunflower oil-in-water emulsions similarly to WPI, but with a slightly wider droplet size distribution. As for time stability of the sunflower oil emulsions at 25 °C, it was seen that droplet size distribution was maintained for 1% WPI and 2% BSFPC, while for 1% BSFPC there was a slight increase. For lemon oil emulsions, BSFPC showed better emulsifying performance than WPI, which required to be prepared with a pH 7 buffer for lemon oil fractions of 40%, to balance the decrease in the pH caused by the lemon oil water soluble components. The stability of the emulsions was improved when maintained under refrigeration (4 °C) for both BSFPC and WPI. The results of this work point out the feasibility of using BSFPC to stabilize O/W emulsions using a low energy system.
... The ionisation mode in the MS was electron impact (EI) mode at the ionisation energy of 70 eV. Identification and quantification of the eluted compounds were as described previously (Cheong et al., 2012). ...
... The HPLC system was controlled using the software, LabSolutions (Shimadzu, Kyoto, Japan). Phenolic acid extracts were filtered with a 0.2 μm PTFE filter (Sartorius, Goettingen, Germany) prior to analysis, and were analysed as described elsewhere (Cheong et al., 2012). External standards were used for identification and quantitation of the phenolic acids. ...
... Terpene hydrocarbons are known to be the major components of citrus essential oils, which contribute to characteristic citrusy and woody notes. It is noted that the calamansi juice from the three countries shared the same monoterpene and sesquiterpene profiles, which were also detected in the calamansi peel (Cheong et al., 2012). For all the calamansi juices, this group of hydrocarbons comprised predominantly limonene, germacrene D and bmyrcene. ...
... Common citrus fruits such as orange (Citrus sinensis), lime (Citrus medica), lemon (Citrus limon), tangerine (Citrus reticulata), grapefruit (Citrus paradisi) are very popular, whereas exotic citrus fruits such as calamansi (Citrus microcarpa), dalandan (Citrus reticulata), mosambi (Citrus sinensis var. mosambi) have gained popularity recently (Cheong, Chong et al., 2012;Cheong, Zhu et al., 2012). As consumer demand for healthy foods increases, the demand for citrus fruit extracts (CFEs) (e.g., freshly extracted fruit juices) is also growing. ...
Article
Despite the widespread belief that citrus fruit extracts (CFEs) are microbiologically safe due to their acidity, limited bactericidal effect results in low applicability as antibacterial agent and outbreaks occurred by acid-adapted pathogens. Here, we examined the antibacterial effects of CFEs [lime (Citrus medica), lemon (Citrus limon), calamansi (Citrus microcarpa)] combined with essential oil components (EOCs; carvacrol and thymol) against non-acid-adapted/acid-adapted Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes under 22 °C for 5 min. CFEs (<20%) alone or small amounts of EOCs (2.0 mM; 0.032%) alone could not inactivate the target bacteria effectively. However, combined treatments exhibited marked synergy: CFE + EOCs eliminated all the bacteria (>6.9 log CFU/ml). Among the CFEs tested, the highest synergism was shown by calamansi, an exotic citrus fruit previously unrecognized as an antibacterial agent. Although acid-adaptation improved bacterial survival, calamansi (<20%) + EOCs (<0.032%) completely inactivated even the most resistant pathogen (E. coli O157:H7). Validation test also showed that all tested commercial juice products also eliminated acid-adapted pathogens when used with EOCs. Physicochemical analysis of tested CFEs (pH measurement and HPLC analysis of components) revealed that low pH and flavanone (hesperidin) did not contribute to the synergistic bactericidal effects. Rather, the high citric acid content is likely to contribute to the strong synergistic effect with EOCs by damaging susceptible bacterial membranes. Sensory scores for CFEs were not altered by addition of EOCs at concentrations up to 1.5 mM. This study provides new insight into the utility of CFEs with EOCs to improve not only the microbiological safety of food products containing CFEs but also their applicability as natural antibacterial complex.
... Hydrophobic extract was obtained referring to Cheong et al. (2012), Bligh and Dyer (1959). Weighed fresh citrus peels (5 g) were extracted with hexane-ethanol mixture solvent (1:2, v/v) at 1:10 ratio sample (w/ v): solvent in an automatic shaker for 24 h at room temperature. ...
Article
Bulky hard peel of Citrus natsudaidai is discarded and not utilized enough in Japan. In this study, the nutritional composition and volatile components of three cultivars of C. natsudaidai peel were determined. Considering the proximate composition and minerals, C. natsudaidai peels showed good carbohydrate and potassium content. The peel color varied probably due to the difference of cultivars. C. natsudaidai peels were extracted and analyzed for free amino acids and for fatty acids and volatile compounds. The amount of free amino acids in the extracts was not enough to affect the taste of extracts. The proportion of individual fatty acid was not comparable to other plant oils, however, typical aroma compounds with citrusy smell were identified. C. natsudaidai extracts could contribute for the utilization as flavoring additives without affecting taste.
... The phenolic acid extracts were analyzed using HPLC (Shimadzu HPLC, Class-VP software version 6.1, Kyoto, Japan) and LabSolution software (Shimadzu, Kyoto, Japan) based on the analytical protocol previously described by Cheong et al. (2012). Prior to HPLC analysis, phenolic extracts were filtered through a 0.20 lm polytetrafluoroethylene (PTFE) membrane (Sartorius, Gottingen, Germany). ...
Article
Modulation of coffee aroma via the biotransformation/fermentation of different coffee matrices during post-harvest remains sparingly explored despite some studies showing their positive impacts on coffee aroma. Therefore, this is an unprecedented study aimed at modulating coffee aroma via the fermentation of green coffee beans with a food-grade fungus Rhizopus oligosporus. The objective of part I of this two-part study was to characterize the volatile and non-volatile profiles of green coffee beans after fermentation. Proteolysis during fermentation resulted in 1.5-fold increase in the concentrations of proline and aspartic acid which exhibited high Maillard reactivity. Extensive degradation of ferulic and caffeic acids led to 2-fold increase in the total concentrations of volatile phenolic derivatives. 36% of the total volatiles detected in fermented green coffee beans were generated during fermentation. Hence, the work presented demonstrated that R. oligosporus fermentation of green coffee beans could induce modification of the aroma precursors of green coffees.
... To prevent confusion, an organic extract from Citrus peel should not be named EO, Chisholm et al., 2003b) although it could simply be named oil (Feger et al., 2001b;Buettner et al., 2003;Craske et al., 2005;Fisher et al., 2008). In fact, medium polarity solvents (diethyl ether, dichloromethane or ethyl acetate) extract more polar and higher MW compounds such as hexadecanal (Naef and Velluz, 2001;Gancel et al., 2002;Chisholm et al., 2003a,b;Cannon et al., 2015), squalene Jiang et al., 2011), linoleic acid (Cheong et al., , 2012Jiang et al., 2011), heptadecanoic acid (Delort and Jaquier, 2009;Jiang et al., 2011) or neophytadiene (Delort and Jaquier, 2009;Delort et al., 2015) than distillation or cold press extraction, and it fails to extract many monoterpene and sesquiterpene compounds which are characteristic of Citrus EOs (Jiang et al., 2011). Moreover, there are other minority extraction methods that use also organic solvents such as simultaneous distillation and extraction (SDE) (Akakabe et al., 2008;Kerdchoechuen et al., 2010;Sun et al., 2014a), microwave-assisted extraction (MAE) (Sun et al., 2014a;Liu et al., 2015), and ultrasonic-assisted extraction (UAE) Darjazi, 2011b;Liu et al., 2012;Sun et al., 2014a;Zhang et al., 2017). ...
Article
Full-text available
The essential oil fraction obtained from the rind of Citrus spp. is rich in chemical compounds of interest for the food and perfume industries, and therefore has been extensively studied during the last decades. In this manuscript, we provide a comprehensive review of the volatile composition of this oil fraction and rind extracts for the 10 most studied Citrus species: C. sinensis (sweet orange), C. reticulata (mandarin), C. paradisi (grapefruit), C. grandis (pummelo), C. limon (lemon), C. medica (citron), C. aurantifolia (lime), C. aurantium (bitter orange), C. bergamia (bergamot orange), and C. junos (yuzu). Forty-nine volatile organic compounds have been reported in all 10 species, most of them terpenoid (90%), although about half of the volatile compounds identified in Citrus peel are non-terpenoid. Over 400 volatiles of different chemical nature have been exclusively described in only one of these species and some of them could be useful as species biomarkers. A hierarchical cluster analysis based on volatile composition arranges these Citrus species in three clusters which essentially mirrors those obtained with genetic information. The first cluster is comprised by C. reticulata, C. grandis, C. sinensis, C. paradisi and C. aurantium, and is mainly characterized by the presence of a larger abundance of non-terpenoid ester and aldehyde compounds than in the other species reviewed. The second cluster is comprised by C. junos, C. medica, C. aurantifolia, and C. bergamia, and is characterized by the prevalence of mono- and sesquiterpene hydrocarbons. Finally, C. limon shows a particular volatile profile with some sulfur monoterpenoids and non-terpenoid esters and aldehydes as part of its main differential peculiarities. A systematic description of the rind volatile composition in each of the species is provided together with a general comparison with those in leaves and blossoms. Additionally, the most widely used techniques for the extraction and analysis of volatile Citrus compounds are also described.
... The phenolic acids extracts were filtered through a 0.20 lm polytetrafluoroethylene (PTFE) membrane while the organic and amino acids extracts were filtered through a 0.20 lm regenerated cellulose (RC) membrane (Sartorius, Gottingen, Germany) before HPLC analysis. The analysis of the phenolic, organic, and amino acids contents of roasted coffees were similar to green coffees (Cheong et al., 2012;Lee et al., 2013;Waters, 1993), using HPLC (Shimadzu HPLC, Class-VP software version 6.1, Kyoto, Japan) coupled to SPD-M20A photodiode array detector (PDA) and LabSolution software (Shimadzu, Kyoto, Japan). Phenolic acids were separated using a Zorbax Eclipse C18 column (4.6 Â 150 mm, 5 lm; Agilent Technologies, Palo, Alto, CA, USA) while organic acids were resolved using a Supelcogel C-610 H column (Supelco, Bellefonte, PA, USA). ...
Article
This study aims to evaluate how changes of the volatile and non-volatile profiles of green coffees induced by Rhizopus oligosporus fermentation of green coffee beans (Part I) translated to changes in the volatile and aroma profiles of light, medium and dark roasted coffees and non-volatile profile of roasted coffee where fermentation effects were most distinctive (light roast). R. oligosporus fermentation resulted in 1.7-, 1.5- and 1.3-fold increases in pyrazine, 2-methylpyrazine and 2-ethylpyrazine levels in coffees of all roast degrees, respectively. This corresponded with the greater extent of amino acids degradation in light roasted fermented coffee. Ethyl palmitate was detected exclusively in medium and dark roasted fermented coffees. The sweet attribute of light and dark roasted coffees were increased following fermentation along with other aroma profile changes that were roast degree specific. This work aims to develop a direct but novel methodology for coffee aroma modulation through green coffee beans fermentation.
... These compounds are hydroxybenzoic acid, anthocyanins, hydroxycinnamic acids, proanthocyanidins, flavonoids, lignans and stilbenes. 33 As shown in Table 1, TFC of the frozen citrus peels was significantly higher than the fresh citrus peels. Based on the results obtained, TFC of fresh lemon peel (50.51 mg QE g -1 FW) and frozen lemon peel (78.15 mg QE g -1 FW) was significantly different. ...
Article
Full-text available
Citrus peel is a functional food. It is rich in antioxidants. This study aims to investigate the antioxidant properties of selected fresh and frozen peels of Citrus species. Frozen and fresh peels of lemon (Citrus limon), key lime (C. aurantifolia) and musk lime (C. microcarpa) were screened for their antioxidant properties such as total phenolic content and total flavonoid content. DPPH radical scavenging activity and ferric ion reducing antioxidant power (FRAP) assays were also determined. Among the three citrus peels, musk lime peel had the significantly highest total phenolic content and total flavonoid content. Frozen citrus peels showed significantly higher antioxidant content than the fresh peels. The frozen peels also showed promising antioxidant activity as indicated by their significantly higher FRAP value compared with fresh citrus peels. Moreover, frozen citrus peel possessed higher antioxidant activity as indicated by its lower EC50 values which ranged between 0.823 ± 0.1 and 3.16 ± 0.92 mg mL-1. A moderately high correlation was determined between FRAP value and total phenolic content (r=0.783), and between FRAP value and total flavonoid content. This study shows that frozen peels of citrus are functional foods and sources of potent antioxidants.
... As one of most important classes of compounds possessing specific bioactivity, phenolic acids have attracted recent scientiEc interest (Cheong et al., 2012;Robbins 2003). Bocco et al. (1998) found that ferulic acid is the main phenolic acid in citrus fruits and that the abundance of phenolic acids in citrus varied as follows: ferulic acid (0.036-1.580 mg/g DW)4sinapic acid (0.030-0.954 mg/g DW)4p-coumaric acid (0.071-0.193 mg/g DW)4caffeic acid (0.006-0.229 mg/g DW). ...
Article
Full-text available
The phenolic compounds in different fruit parts including the flavedos, albedos, segment membranes, juice vesicles and seeds of nine grapefruit varieties cultivated in China were determined and their antioxidant capacities were evaluated using three methods. Naringin and neohesperedin were the dominant flavonoids in all grapefruit tested. Fenghongtangmuxun and Jiwei flavedo had the highest contents of naringin (5666.82 μg/g DW) and neohesperedin (1022 μg/g DW), respectively. Gallic acid was the major phenolic acid in all grapefruit tested, and Jiwei juice vesicles had the highest content of gallic acid (343.7 μg/g DW). Fenghongtangmuxun juice vesicles were rich in chlorogenic acid (110.23 μg/g DW), caffeic acid (53.86 μg/g DW) and ferulic acid (23.12 μg/g DW). Overall, the flavedo was rich in flavonoid, while juice vesicle had high amounts of phenolic acid. The Jiwei, Fenghongtangmuxun, Maxu, Huoyan and Hongmaxu grapefruit cultivars contained more phenolics and exhibited higher antioxidant capacities than Shatianyou and Liangpingyou pummelos, and were good sources of natural phytochemical antioxidants.
... In Mexico, during the extraction process of naranjita juice, important amounts of bagasse (peel and seeds) are obtained and commonly wasted (Delgado-Nieblas et al., 2017). However, several authors (Cheong et al., 2012;Yu, Lou, Chiu, & Ho, 2013) have reported that the peel of this fruit contains high contents of bioactive molecules such as phenolic compounds (PC), flavonoids, carotenoids, and pectins, whose consumption could have benefits in human health. ...
Article
Full-text available
The aim of this study was to evaluate the physicochemical, phytochemical, and antioxidant changes in different stages (unprocessed mixture [UM], extruded pellet [EP], and expanded product [EXP]) during the production of indirectly expanded snacks by microwave. Four mixtures (from corn starch/whole yellow corn flour), adding naranjita bagasse (NB) and/or skimmed milk powder, were used. Ash content, water absorption index (WAI), water solubility index (WSI), soluble dietary fiber (SDF), free phenolic compounds (FP), bound phenolic compounds (BP), and antioxidant activity (AOA) were higher in EP than in UM, whereas lipids, crude fiber, total carotenoids (TC), and total and insoluble dietary fiber (TDF and IDF) were lower. Also, WAI, WSI, color b*, FP, SDF, and AOA from FP were higher in EXP than in EP, while BP, TC, TDF, IDF, and AOA from BP were lower. The snacks with added NB presented acceptable sensory characteristics. Snacks with appropriate nutritional/nutraceutical properties from raw materials rich in bioactive compounds can be produced. Based on the high demand of consumers for purchasing healthier products, the food industry has shown great interest in improving the nutritional properties of some products that are rich in calories, but very poor in nutrients. The incorporation of raw materials rich into bioactive compounds, such as cereals and by‐products of the citrus industry, as well as the addition of milk powder for the fortification of snack foods has been highly recommended. Several studies have shown increased nutritional properties and potential health benefits on humans by the addition of these materials. Furthermore, there is little information on the physicochemical, phytochemical, and antioxidant changes that are generated during the processing of indirectly expanded snack foods.
... Before sensory evaluation and, as necessary, during the session, the different concentration standard solutions of benzeneacetaldehyde, linalool, linalool oxide, 2-ethyl-3-methylpyrazine, 1,2,4-trimethoxybenzene diluted with ethanol (by activated carbon) were used to instruct the panelists to be familiar with the green, floral, sweet, roasted and stale notes, and their aroma intensities ( Table 3). The panelists were asked in a random order to rate the extracts for green, floral, sweet, roasted and stale notes, and gave a score within 0-9 according to relevant references and ISO 8589 [28,29], in which zero indicates an unperceived attribute intensity and nine indicates a very strong attribute intensity. After each sniff, an interval gap of 20 s in fresh air was used refresh the olfactory fatigue, which was sufficient between individual odor assessments. ...
Article
Full-text available
The unpleasant stale note is a negative factor hindering the consumption of instant ripened Pu-erh tea products. This study focused on investigating volatile chemicals in instant ripened Pu-erh tea that could mask the stale note via sensory evaluation, gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O) analyses. GC-MS and GC-O analyses showed that linalool, linalool oxides, trans-β-ionone, benzeneacetaldehyde, and methoxybenzenes were the major aroma contributors to the simultaneous distillation and extraction (SDE) extract of instant ripened Pu-erh tea. Sensory evaluation showed that the SDE extract had a strong stale note, which was due to methoxybenzenes. By investigating suppressive interaction among flavour components, the stale note from methoxybenzenes was shown to have reciprocal masking interactions with sweet, floral, and green notes. Moreover, the validation experiment showed that the addition of 40 μg/mL of trans-β-ionone in the instant ripened Pu-erh tea completely masked the stale note and improved the overall aromatic acceptance. These results elucidate the volatile chemicals that could mask the stale note of instant ripened Pu-erh tea products, which might help to develop high quality products made from instant ripened Pu-erh tea.
... The adequacy of Elovich model to fit experimental data to heterogeneous catalyst surfaces helps to explain the fit in predicting the adsorption of congo red onto calamansi peels. This form of kinetic law involves a variation of the energetics of chemisorption with the active sites resulting to different activation energies for chemisorption since the peels of calamansi have been found to contain hydroxycinnamic acids and phenolic acids 33 . Since calamansi and orange belong to the same family, and both peels contain various functional groups; electrostatic attraction, organic properties, and structure of dye molecules can influence the adsorption process. ...
Article
Full-text available
Unripe calamansi peels were prepared and used as a bioadsorbent in the removal of congo red from an aqueous solution using batch adsorption studies. The efficiency of adsorption was evaluated by varying adsorbent dose and contact time. The removal of congo red increased at higher adsorbent dose and longer contact time. The overall rate of adsorption processes appeared to be in accordance with the pseudo-second order reaction mechanism. Higher initial adsorption rate, extent of surface coverage, and activation energy were favored at a lower adsorbent dose, while the intraparticle diffusion was relatively faster at a higher adsorbent dose. The intraparticle diffusion, Elovich, and MacArthur-Wilson models were adequate in describing the chaotic behavior of the kinetic processes involved in the removal of congo red dye onto unripe calamansi peels.
... Pomelo (Thavanapong, 2006) Calamansi (Chong et al, 2012) Korean Citrus (Kang et al., 2013) beta-Phellandrene Table VIII showed the similarity of components between LEO and the peels of pomelo, calamansi, and Korean citrus. It can e noted that among the four (4) citrus species, the common compounds present are β-myrcene, β-ocimene, and Dlimonene. ...
... The health benefits of this citrus fruit have been attributed to their high content of phenolic compounds, including coumarins, flavonoids, lignin's, phenolic acids, and tannins [11]. Phenolic acids such as caffeic, p-coumaric, ferulic, and sinapic acids were found in C. microcarpa peel [12]. These acids were reported to exhibit high antioxidant activity [13]. ...
Article
Full-text available
Green synthesis of particles involves the use of safe biological agents as an eco-friendly and cost-effective alternative to chemical synthesis. In this study, silver particles were biosynthesised by using silver nitrate and aqueous Citrus microcarpa peel extract as the reducing and stabilising agent. The synthesised silver particles were confirmed and characterised by UV-Vis spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS). The UV-Vis spectrum showed surface plasmon resonance (SPR) with maximum peak intensity around 450 nm. The DLS studies show that silver particles have an average Z-diameter value of 235 nm with a polydispersity index of 0.363, which indicates the presence of agglomeration. The reaction parameters have a significant effect on the formation of silver particles. The highest absorbance recorded was 1.42 obtained under conditions of 72 hours reaction time, using 5 wt.% peel extract that reacted with 8 mM silver nitrate solution, while the ratio of solution of peel extract to silver nitrate was fixed at 1:5. Silver particles were successfully synthesised by Citrus microcarpa peel extract, which has the potential to replace the chemical method. Abstrak Sintesis hijau partikel melibatkan penggunaan agen biologi yang selamat sebagai alternatif yang mesra alam dan keberkesanan kos dibandingkan dengan kaedah sintesis kimia. Dalam kajian ini, partikel perak disintesis dengan menggunakan nitrat perak dan ekstrak kulit Citrus microcarpa berair sebagai ejen penurunan dan penstabilan. Partikel perak yang disintesis telah dikaji dan dicirikan dengan menggunakan analisis spektoskopi UV-Vis, mikroskop imbasan elektron (SEM), spektroskopi tenaga sinar-X (EDX), dan penyerakan cahaya dinamik (DLS). Spektrum UV-Vis menunjukkan permukaan resonan plasma (SPR) pada panjang gelombang maksimum sekitar 450 nm. Kajian PCD menunjukkan bahawa purata saiz bagi partikel ialah 235 nm dan indeks poliserakan adalah 0.363 yang membuktikan pengaglomeratan partikel. Parameter reaksi mempunyai kesan yang signifikan terhadap pembentukan partikel perak. Panjang gelombang tertinggi yang direkodkan adalah 1.42 yang diperolehi dalam keadaan masa 72 jam dengan menggunakan ekstrak 5 wt.% yang bertindak balas dengan larutan perak nitrat 8 mM, manakala nisbah larutan kulit ekstrak ke nitrat perak ditetapkan pada 1:5. Partikel perak boleh disintesis dengan menggunakan ekstrak kulit Citrus microcarpa yang mempunyai potensi untuk menggantikan kaedah sintesis kimia.
... The reaction mixture was refluxed for two hours and then left overnight where the complexes precipitated, filtered, washed with distilled water, and dried in vacuum desiccators over P4O10. The melting points of the complexes were over 300 ºC (Cheong et al., 2012). For the analysis of the metal content, the complexes were digested and decomposed with aqua regia (a mixture of HCl acid and HNO3 at a ratio of 3:1). ...
Article
Full-text available
The present experiment evaluated the inclusion of chelated phytogenic feed additives mixture in the diet of lactating cows for the first 3 months of lactation. A week before calving, thirty multiparous Friesian cows were divided into three treatments in a complete randomized design and fed a basal diet without supplementation (Control treatment), or the control diet supplemented with chelated phytogenic additives at 3 g (PHY3 treatment), or at 6 g/cow/d (PHY6 treatment). Menthol, levomenthol, β-linaloolm, anethole, hexadecanoic acid and pmenthane were the principal compounds identified in the additives mixture. Milk production, total solid, protein, fat, and lactose were increased with PHY3, but decreased by PHY6 (P<0.01). Whereas the PHY3 treatment increased (P<0.05) milk contents of Ca and Zn, PHY3 and PHY6 treatments increased (P<0.05) milk Fe and Mn concentrations. Though the PHY3 treatment increased (P<0.05) nutrient digestibility, the PHY6 treatment decreased (P<0.05) the digestibility of organic matter, crude protein and neutral detergent fiber. The PHY3 treatment increased (P<0.05) ruminal volatile fatty acids (VFA) concentration and proportional acetate and propionate and decreased butyrate, while the PHY6 treatment decreased ruminal VFA concentration and proportional acetate. The PHY3 treatment increased (P<0.05) serum total protein, glucose, total antioxidant capacity, and the concentrations of Ca and Zn. Both PHY3 and PHY6 treatment decreased (P<0.05) the concentrations of serum triglycerides, and cholesterol. Daily inclusion of 3 g/cow of chelated feed additives mixture in diet of lactating cows improved milk production and ruminal fermentation, but additives dose of 6 g/cow/d had negative impact on cows’ performance.
... [46] As shown in Figure 6, drying resulted in an obvious reduction in the signal intensities of 2-hexanone, 2-butanone, 2-methylpropionic acid, 1-pentanol, and 5-methyl-2-furanmethanol. These volatiles have been previously reported in citrus products, [14,47,48] and the decreased amount of these compounds can be ascribed to the high air velocity and long-time drying process employed in this study. [9] The concentration of linalool oxide in the yellow citrus peels was also reduced after drying. ...
Article
Citrus peels are considered as an agricultural waste with negative environmental impacts. In the present study, yellow (ripe) and green (unripe) Citrus reticulata peels were dried in a hot air impingement dryer and the effect of drying temperatures (40, 50, 60, and 70 °C) on the drying characteristics, volatile compounds, and antioxidant capacity were explored. The results showed that the drying time of samples was reduced by more than 50% when the drying temperature was increased from 40 to 70 °C. A total of 56 peaks and 29 volatile components were identified by headspace-gas chromatography-ion mobility spectrometry. Drying caused an obvious reduction in the concentration of linalool oxide, benzaldehyde, (E)-2-heptenal, and 1-pentanol, and an increment in the concentration of pentanal, decanal, linalool, and (E)-2-hexenol. Principal component analysis showed that samples under different treatments were clearly distinguished. Drying resulted in a significant reduction of 2,2‐diphenyl‐1‐picrylhydrazyl and ferric reducing antioxidant power. These findings will contribute to a better understanding of citrus peel drying as well as their volatile profiles and antioxidant capacity changes during drying.
... med in the past years due to their abundance, economic value, and lack of use. Calamansi (Citrofortunella microcarpa), a common green citrus fruit, is native and abundant in various Asian countries including the Philippines. The peel of calamansi has been found to contain different phenolic compounds such as phenolic acids, tannins, and flavonoids (Cheong et. al, 2012;Lou & Ho, 2017), which are said to be effective agents of biosorption. Meanwhile, dalandan (Citrus aurantium) is a variety of fruit that belongs in the species of sweet oranges of the citrus family and is native to the Philippines and most tropical warm countries. The peel of dalandan contains flavonoids such as aurantiamarin, auranetin, ...
Conference Paper
Full-text available
Heavy metal presence in water bodies has become a matter of concern due to their impacts on human health and the environment. Crop-based waste materials for heavy metal removal from aqueous solutions have since been investigated to help address issues in both solid waste management and environmental pollution. In this study, calamansi (Citrofortunella microcarpa) and dalandan (Citrus aurantium) peels were investigated for their percent removals and adsorption capabilities under experimental parameters including pH level, sorbent mass (m), and contact time (CT) through batch adsorption studies. Based on the highest percent removal (%R) of metal ions for each parameter, optimum conditions were determined for the biosorption of Ni 2+ (pH 4, 0.50 g, 60 mins) and Zn 2+ (pH 6, 0.25 g, 120 mins) in calamansi peels. Biosorption in dalandan peels yielded the following optimum conditions: Ni 2+ (pH 4, 0.50 g, 10 mins), and Zn 2+ (pH 5, 0.25 g, 30 mins). Adsorption kinetics were observed to be in accordance with a pseudo-second order Lagergren model. In summary, the results show that calamansi and dalandan peels exhibit considerable potential as heavy metal biosorbents which merit future studies on their efficiency, and their application to actual environmental water samples.
... Nevertheless, in most cases, the species and/or the varieties remained unspecified. Meanwhile, It is interesting to note that the chemical composition of the oil is significantly affected by the vegetative stage of plant, storage condition and extraction method and citrus peel oil is particularly prone to quantitative and quantitative changes due to genotype, origin, climate, season, ripening stage, etc. (Caccioni et al., 1998;Venkateshwarlu and Selvaraj, 2000;Vekiari et al., 2002;De Pasquale et al., 2006;Njoroge et al., 2006;Espina et al., 2011;Bourgou et al., 2012 ;Cheong et al., 2012 ). Regarding the inhibition and reduction in numbers of foodborne pathogens by mandarin group EOs, scarce reports have been carried out (Viuda-Martos et al., 2008;Chutia et al., 2009;Espina et al., 2011;Bourgou et al., 2012). ...
Article
Full-text available
The present investigation reports on the chemical composition of three citrus fruit essential oils (mandarin [Citrus reticulata], wilking [Citrus reticulata cultivar wilking] and clementine [Citrus clementina]) from Algeria, and examines their antioxidant and antimicrobial activity against eight spoiling and pathogenic microorganisms. The chemical composition of the essential oils obtained from the peels, by hydrodistillation, was analyzed by Gas chromatography–mass spectrometry (GC-MS). 12 compounds were identified and limonene was the common major component for the three essential oils (77- 97%).The disc agar diffusion technique indicated mandarin essential oil (EO), as evidenced by their zones of inhibition, as the best growth inhibitor followed by clementine and wilking essential oils. Among the tested microorganisms, the oils was very active against Candida albicans, Escherichia coli, Lysteria innocua, Methicillin-Resistant S. aureus and Staphylococcus aureus with an inhibition zone varied from 9.16 to 27.63 mm. Minimal inhibitory concentration (MIC) of different EOs was for all 5 μL/mL against the sensitive microorganisms studied. All citrus oils studied exhibited antioxidant activity as DPPH free radical scavenger and reducing power in dose dependent manner. Mandarin oil showed the strongest activity compared to clementine and wilking essential oils. The oils may be recommended as safe plant based antimicrobials as well as antioxidants for enhancement of shelf life of food commodities.
Article
Deterioration of aromas of pummelo essential oil (EO) induced by sunlight was compared to those induced by heat and oxygen exposure using the techniques of sensory evaluation and GC-MS analysis. The sunlight-exposed EO was found to possess an oily off-flavor odor, which was significantly different from its counterparts induced by oxygen and heat. The strong oily note of the sunlight-exposed EO was attributed to the existence of linalool oxides and limonene oxides, as well as the lack of neral and geranial, for which UV sunlight was revealed to be the critical contributor causing the chemical reactions for the aroma changes. The results demonstrated that UV sunlight could significantly affect the aroma of the pummelo EO, providing valuable information that will benefit the production and storage of EO-based aromatic products.
Article
Calamondin fiber (CF) was extracted and incorporated into dough and steamed bread. Results showed that the substitution of wheat flour by CF resulted in a stiffer and less extensible dough. Both Peleg-Normand and Wiechert models fitted well to the stress relaxation data of steamed bread. Hardness of steamed bread increased with the increase of CF substitution, but the cohesiveness, specific volume and elasticity decreased with the fiber substitution. As CF substitution was increased from 0 to 9%, total phenolic content and DPPH radical scavenging capacity of the steamed bread were improved by about 23 and 34, 52 and 53, as well as 77 and 74%, respectively. In sensory evaluation, steamed breads with 0 - 6% CF had similar flavor, texture and overall scores. These results suggest that the addition of 3 or 6% CF can produce healthy and acceptable fiber-enriched steamed bread with higher phytochemicals and antioxidant capacity.
Article
To investigate the quality of essential oils (EOs) of the major pummelo (Citrus maxima) fruits in China, the sensory characteristics and volatile components of the essential oils (EOs) of Guan Xi, Sha Tian, and Liang Ping pummelos were analyzed by sensory evaluation and gas chromatography-mass spectrometry (GC-MS). The results of the sensory evaluation showed that the three EOs had similar aroma. Guan Xi pummelo EO had a strong floral scent, while the aroma of Sha Tian pummelo EO was similar to mint. Liang Ping pummelo EO had a relatively strong citrus and sweet scent. The GC-MS results showed that although the three types of EOs contain the same major volatile constituents, e.g., d-limonene (476, 150-741, and 595 μg/mL) and β-myrcene (13, 859-207, and 255 μg/mL), Guan Xi pummelo EO had higher concentrations of β-ocimene, linalool, and some aldehydes. The odor activity values (OAVs) showed that Guan Xi pummelo EO (5,015,965) had a much higher OAV than Sha Tian (1,307,088) and Liang Ping (1,159,532) pummelo EOs. Furthermore, the strong floral scent of Guan Xi pummelo EO mainly originated from β-myrcene (2,093,489) and linalool (387,578). The results indicated that although the three pummelo EOs had similar aroma and volatile components, their qualities differed to a certain extent. These results provide a theoretical basis for further comprehensive development and utilization of pummelo EOs in China. ©, 2014, South China University of Technology. All right reserved.
Article
Volatile extracts were prepared from the peel of pummelo by cold pressing (CP), water distillation (WD), simultaneous distillation and extraction (SDE), microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE) and supercritical CO2 fluid extraction (SFE). They were analysed by sensory evaluation and gas chromatography–mass spectrometry (GC-MS). The former technique showed that the CP essential oil (CP-EO), MAE and UAE extracts possessed similar odour profiles to the natural pummelo odour, whereas the SDE extract and WD essential oil (WD-EO) presented the fermented/overripe and alcohol/pungent notes, and the SFE extract had a sweet note. Although the GC-MS analyses revealed the six extracts had a certain degree of differences in their compositions, they had similar major volatiles, including limonene (301 476–497 028 µg/ml), β-myrcene (86 400–230 400 µg/ml), β-pinene (1370–7129 µg/ml), linalool (1916–4482 µg/ml) and germacrene D (1165–2327 µg/ml). Analyses of odour activity values (OAVs) and cluster analysis revealed the fermented/overripe and alcohol/pungent notes of the SDE extract and WD-EO were attributed to nerol, geraniol and linalool oxide. The sweet note of the SFE extract was ascribed to citronellal and limonene oxide. Besides, a lack of limonene, neral and geranial resulted in a light green aroma of the SFE extract. This information might be valuable for further development of aromatically desirable products from citrus fruits. Copyright © 2014 John Wiley & Sons, Ltd.
Article
This study evaluated the impact of added diammonium phosphate (DAP) and a L‐leucine‐L‐phenylalanine mixture (Leu+Phe) on durian wine fermentation by Saccharomyces cerevisiae var. bayanus EC‐1118. Changes in yeast cell population, oBrix, sugars, organic acids and pH were similar in all fermentations, regardless of nitrogen supplementation at a concentration of 150 mg N L−1. The supplementation of Leu+Phe accelerated the utilisation and reduced the formation of volatile sulphur compounds such as diethyl disulphide, ethyl thioacetate and 2‐(ethylthio)ethanol, which were 64.3%, 26.0% and 48.4% lower than the control, respectively. Nevertheless, the supplementation of Leu+Phe heightened the production of isoamyl alcohol, 2‐phenylethyl alcohol and their corresponding esters, especially isoamyl acetate was 1.6 times and 2‐phenylethyl acetate was 26.5 times higher than the control. The supplementation with DAP exerted negligible effects on the volatile composition. The results of this study suggest that the addition of specific amino acids may be a novel approach to manipulating durian wine flavour by suppressing or accentuating the formation of certain aroma compounds.
Article
Aldehydes are key aroma contributors of citrus essential oils. White Guanxi honey pummelo essential oil (WPEO) was investigated in its aldehydes constituents and their transformations induced by UV irradiation and air exposure by GC-MS, GC-O, and sensory evaluation. Nine aldehydes, i.e., octanal, nonanal, citronellal, decanal, trans-citral, cis-citral, perilla aldehyde, dodecanal, and dodecenal were detected in WPEO. After treatment, the content of citronellal increased, but the concentrations of other aldehydes decreased. The aliphatic aldehydes were transformed to organic acids. Citral was transformed to neric acid, geranic acid and cyclocitral. Aldehyde transformation caused a remarkable decrease in the minty, herbaceous and lemon notes of WPEO. In fresh WPEO, β-myrcene, d-limonene, octanal, decanal, cis-citral, trans-citral, and dodecenal had highest odour dilution folds. After the treatment, the dilution folds of decanal, cis-citral, trans-citral, and dodecenal decreased dramatically. This result provides information for the production and storage of aldehydes-containing products.
Article
Cloud loss of orange juice could be effectively inhibited by centrifugal treatment, but it can induce flavor changes, which become a new challenge for the industry. This work aims to investigate the effect of centrifugation on flavor changes in orange juice and explore its possible mechanism. Taste- and aroma-related attributes were analyzed, and pectin was characterized. Results indicated that pH (4.00), total soluble solid (9.67 °Brix), titratable acidity (0.42%), sucrose (44%), fructose (29%), and glucose (27%) were less affected by centrifugation (P > 0.05). However, aroma compounds significantly changed (P < 0.05), where terpenes and alcohols tended to be distributed in pulp and serum after centrifugation, respectively. Pearson correlation analysis showed that aroma compound distribution induced by centrifugation was highly related to chelator-solubilized pectin fraction and sodium carbonate-solubilized pectin fraction (|R| > 0.9). In general, centrifugation clearly changed aroma of orange juice, which was mainly affected by pectin characteristics.
Article
The fermentation of green coffee beans by Yarrowia lipolytica led to significant changes in the volatile and non-volatile profiles of green coffees (Part I). Therefore, the objective of this continuation study was to evaluate the effects of fermentation after roasting by characterizing the volatile profiles of coffees at three different roast levels and non-volatile profiles of coffee where the effects of fermentation on volatiles were most prominent (light roast). Y. lipolytica fermentation led to significant changes in the volatile profiles of roasted coffees which arose from both the modification of aroma precursors and the retention of volatile profile changes observed in green fermented coffees. The levels of 4-vinylguaiacol and 4-vinylphenol were 1.2-fold and 1.6-fold higher in light roasted fermented coffees respectively and could be explained by the higher levels detected in green fermented coffees before roasting. The levels of γ-butyrolactone were 5 times higher in light roasted fermented coffees than unfermented coffees. The increase in sulfur compounds levels and decrease in ketones levels were attributed to changes in the concentrations of aroma precursors like sugars and amino acids. Thus, this study highlighted the potential of utilizing yeast fermentation of green coffee beans for coffee aroma modulation.
Article
Hydrophobic materials extracted from citrus wastes, both peel of mandarin fruits and leaf of mandarin trees were used to treat food-grade Kraft paper. The chemical compounds of the extracts were identified by gas chromatography–mass spectroscopy and infrared spectroscopy, and their antioxidant activities were determined using a free radical scavenger agent (2,2-diphenyl-1-picryl-hydrazyl-hydrate, DPPH). Water vapor permeability, air transmission rate, peroxide value, and microstructure of treated and original papers were also determined. The experimental results showed that: (i) most components of the peel or peel/leaf extracts were terpenes; (ii) free volume existed among cellulose macromolecule chains of the original paper, occupied by a part of extract materials, and another part of the extracts was formed a thin layer on the paper surfaces; and (iii) air and water barrier properties and antioxidant activity of the treated papers were improved, indicating that the extracts were efficient materials for food packaging applications.
Article
Objective: To investigate effects of oxygen and heating on aromas and volatile components of pummelo essential oil (PEO). Method: The PEOs were analyzed by sensory evaluation, gas chromatography coupled with mass spectrometry (GC-MS), GC-olfactometry (GC-O) and sensory reconstruction analysis. Results: The PEO co-treated by oxygen and heating exhibited significant differences in both aromas and volatile compositions from those of the fresh, the nitrogen-protected, the heated and the oxygen-exposed PEOs. The strong sweet and floral notes of the oxygen and heating co-treated PEO were attributed to high concentration of limonene oxides; the strong minty note was resulted from the increase of L-carvone. Conclusion: The results indicate that limonene oxides and L-carvone could significantly change the aroma of PEO co-treatment by oxygen and heating, providing valuable information for the production and storage of aromatic products of PEO.
Article
Background: Traditional view considers that the long-term stored Chenpi (dried citrus peel) has better health efficacies as compared with the fresh Chenpi, but the detailed mechanism remains obscure. Results: The three water-soluble pectic polysaccharides (CPP1, CPP5 and CPP10) were obtained from one-year, five-year and ten-year Chenpi, respectively, and their physicochemical characteristics and intestinal immunomodulating activities were investigated and compared. Our results showed that CPP5 and CPP10 showed the lower dynamic viscosity and degree of methylesterification, as well as the higher molecular heterogeneity as compared with CPP1. The monosaccharide composition analysis indicated that CPP1 was composed of arabinose, galacturonic acid, galactose and a little of rhamnose, however CPP5 and CPP10 consisted of arabinose, galacturonic acid, galactose, glucose, xylose and a little of rhamnose. With the extension of storage period of Chenpi, the content of soluble conjugate phenolic acids increased in the pectic polysaccharide. Furthermore, it was proven that the pectic polysaccharides extracted from the five-year and ten-year Chenpi could significantly enhance the proliferation of bone marrow cells via activating the Peyer's patch cells in vitro. Conclusion: The present study demonstrated the differences of the pectic polysaccharides from Chenpi with different storage periods, and proved that the pectic polysaccharides extracted from the long-term stored Chenpi had the more significant intestinal activities than that from the fresh Chenpi. This phenomenon might partly explain why the long-term stored Chenpi had better health care effects.
Article
High‐temperature treatment of fruit is a developing way of decreasing nutrient loss and preventing decay. Its effect on calamansi (Citrus microcarpa) has not yet been reported. This study aims to study the effects of high‐temperature treatment via dielectric properties. The results show that high‐temperature treatment of calamansi suppresses the dielectric constant between 200 MHz and 20 GHz and alters loss factor between 200 MHz and 10 GHz. Storage at room temperature can affect loss factor between 4.5 and 10 GHz. These results may indicate that the dehydration process first affects the loss factor from 4.5 to 10 GHz, and then from 200 MHz to 4.5 GHz. This study may be favorable for evaluating calamansi's quality during storage and transportation. Moreover, the loss factor under 10 GHz is promising as an index for monitoring the water deficit and for assessing the adopted pre‐treatment on calamansi. The quality inspector can use nondestructive examination ways to measure the dielectric property for evaluating Citrus microcarpa’s quality and storage time after harvest. Moreover, the adopted pre‐treatment may be speculated.
Article
Full-text available
Jeruk Kalamansi (Citrofortunella microcarpa) merupakan salah satu komoditi unggulan Provinsi Bengkulu yang diolah menjadi sirup. Hasil samping industri sirup jeruk kalamansi berupa kulit, pulp, biji, dan cairan hasil pengendapan. Hasil samping ini berpotensi mengandung senyawa aktif berupa concrete, oleoresin dan atau minyak atsiri. Penelitian ini bertujuan untuk mendapatkan kondisi proses maserasi optimum dalam produksi concrete dari hasil samping industri sirup jeruk kalamansi yang berbentuk padatan (kulit dan pulp). Variabel yang digunakan pada penelitian ini adalah lama maserasi (6, 12, dan 24 jam) dan rasio antara berat bahan dan volume pelarut (1:1, 1:2, dan 1:3). Pelarut yang digunakan adalah etanol 96%. Respon yang diharapkan pada penelitian ini adalah rendemennya. Pengolahan data menggunakan metode respon permukaan pada software Minitab 16. Berdasarkan analisa varian diketahui bahwa efek linear lebih signifikan dibandingkan efek kuadratik, sehingga persamaan optimasi yang didapat adalah Y = 25,1667 + 6,1167 X1 + 1,2397 X2. Titik optimum belum tercapai. Rendemen maksimum diperoleh sebesar 54,6823 %, didapatkan pada lama maserasi 24 jam dan rasio berat bahan dan volume pelarut 1:1,75. Karakteristik mutu concrete kulit & pulp jeruk kalamansi yaitu berat jenis 0,985, bilangan asam 1,838, dan indeks bias 1,354.
Article
The effect of rootstocks on flavor-related compounds, and nutrition and processing quality of Kinnow mandarin (C. nobilis × C. deliciosa) was investigated by targeted metabolomics approach employing LC–MS/MS and GC–MS/MS. Fruit samples were collected from mature trees grafted on six rootstocks, viz. Rough lemon 1 (C. jambhiri Lush), Rough lemon 2 (C. jambhiri), Sour orange (C. aurantium ‘Karun Jamir’), Cleopatra mandarin (C. reshni), Pectinifera (C. × depressa ‘Pectinifera’), and Shekwasha (C. × depressa ‘Shekwasha’). The data revealed significant differences in the concentration of some primary and secondary metabolites. Sour orange rootstock showed a higher concentration of polyphenolics and limonoid aglycones and a lower concentration of sugars, organic acids and aroma volatiles as compared to Shekwasha and Pectinifera. Rough lemon and Cleopatra rootstock presented desired concentration of organic acids and limonoid aglycones with moderate concentration of vitamins (B-complex and C), polyphenolics, and aroma volatiles. Principal component analysis (PCA) segregated Kinnow fruit grafted on different rootstocks into different PCs based on primary and secondary metabolites. Such differences indicate the influence of rootstock on Kinnow metabolome. This study highlights the importance of metabolomics in illuminating metabolic profile of citrus, thereby aiding in the selection of the desired rootstock for intended fruit quality.
Article
Full-text available
The essential oil of Citrus microcarpa peels was applied in many fields, and the methods to improve the efficiency of citrus exploitation were increasingly concerned. In this study, citrus essential oil was extracted from calamondin by hydrodistillation. This study was carried out to investigate the factors affecting the distillation of essential oils. The highest performance of the distillation process was 2.45 % with optimal conditions (material-water ratio of 1:3 g/mL, time of 2 h, the temperature of 120 ºC). Moreover, calamondin (Citrus microcarpa) peels oil extract was analyzed by gas chromatography-mass spectrometry (GC-MS). The primary compound of calamondin essential oil include limonene 96.925 %, β-myrcene 1.424 %, 1R-α-pinene 0.561 %, cyclohexene 0.343 %, 1R-α-pinene 0.561 % and β-cubebene 0.598 %.
Thesis
Full-text available
The MPhil study presented in this thesis was an extension of a collaborative research partnership between the Indigenous Bioresources Research Group (IBRG) of Macquarie University and Chungtia village (Chungtia Senso Mokokchung Town, CSMT), Nagaland, for documentation of ethnobotanical knowledge of Chungtia village Elders and healers as well as phytochemical and biological activity investigation and isolation of bioactive constituents from Nagaland medicinal plants. The project was initiated by Meyanungsang Kichu, a Nagaland person, who conducted an ethnobotanical study of medicinal plants used by Chungtia villagers and documented 135 plants for their various ethnomedicinal and ethnobotanical applications. This MPhil study completed an up to date literature review of the 135 medicinal plants, then investigated the antimicrobial potential of those plants used by Chungtia villagers for skin conditions, conducted antimicrobial screening of a selection of these, and finally investigated in detail one plant for its antimicrobial activity and bioactive constituents. A comprehensive literature review covering traditional usages of all 135 plants by other Indigenous traditional healers’ worldwide and phytochemical and biological properties of these plants was conducted. This revealed that the traditional usages by the Chungtia community of 93 of their medicinal plants are in agreement with the uses of other Indigenous communities. Thirteen species were found to have no reports on their traditional uses, other than our first-hand accounts of the Chungtia community. Out of 93 species that were found to be used in a similar way by other communities, 80 had traditional uses that were consistent with pharmacological studies that have been reported in the literature and 55 of these plants had also had phytochemical studies conducted that showed bioactive compounds that aligned with their traditional uses by the Chungtia villagers. A detailed literature review was conducted on the antimicrobial properties and relevant phytoconstituents of 35 plants used by the Chungtia villagers for skin related conditions of a possible microbial origin. This highlighted twelve species with either no antimicrobial properties reported and/or no antimicrobial compounds identified. Out of these, seven species (Dendrocnide sinuata, Duabanga grandiflora, Erythrina stricta, Eurya acuminata, Holboellia latifolia, Maesa indica and Prunus persica) that were available for collection were selected for antimicrobial screening. The antimicrobial screening of the 70% aqueous ethanolic extracts of the plants (D. sinuate stem, D. grandiflora stem bark, E. stricta stem, E. acuminata leaves, H. latifolia leaves, M. indica leaves and P. persica roots) was performed using disc diffusion and MTT microdilution assays against the human pathogenic microorganisms Staphylococcus aureus (susceptible S. aureus), methicillin resistant S. aureus (MRSA) and multi drug resistant S. aureus (MDRSA), susceptible beta-lactamase negative Escherichia coli (β- E. coli), β- lactamase positive (antibiotic resistant) E. coli (β+ E. coli), Pseudomonas aeruginosa, Streptococcus pyogenes, Salmonella typhimurium and Candida albicans. The highest inhibitory activities were exhibited by the P. persica root extract, with MIC values of 156 μg/mL for all tested S. aureus strains. Based on the antibacterial screening results, P. persica was selected for further biological and chemical investigations for its antibacterial constituents. The 70% aqueous ethanolic P. persica roots extract was subjected to partitioning with different polarity solvents (n-hexane, dichloromethane, ethyl acetate). The most potent inhibitory activity was observed for the n-hexane and ethyl acetate partitions against susceptible and resistant strains of S. aureus. The GS-MS analysis of the n-hexane partition revealed the presence of eight constituents, out of which three were reported in the literature as antibacterial against S. aureus. TLC bioautographic methods reported in the literature were trialled with the aim to develop the most appropriate technique for the bioautography guided isolation process. The overlay method was found to be the most effective for the purpose of this study. TLC bioautography guided isolation by normal phase chromatography, size exclusion chromatography and preparative TLC led to the isolation of β-sitosterol (5.1) from the n-hexane partition and afzelechin (5.2) and ent-epiafzelechin-(2α→O→7’,4α→8’)-(-)-ent-afzelechin (5.3) from the ethyl acetate partition. The structures of these three compounds were determined based on various spectroscopic methods, including mass spectrometry, nuclear magnetic resonance spectroscopy, Infrared spectroscopy and circular dichroism. β-Sitosterol was found to be moderately active (MIC 1250 μg/mL) against P. aeruginosa as well as weakly active (MIC 2500 μg/mL) against susceptible strains of S. aureus, E. coli and S. typhimurium. ent-Epiafzelechin-(2α→O→7’,4α→8’)-(-)-ent-afzelechin showed good antibacterial activity against all the tested strains of S. aureus (MIC 156 μg/mL for susceptible and 312 μg/mL for resistant) as well as weak activity against the susceptible strains of E. coli, P. aeruginosa and S. typhimurium (MIC 2500 µg/mL, for all bacteria). This is the first report of this compound possessing antibacterial activity. The antimicrobial properties of afzelechin were not tested due to the small quantity of sample.
Conference Paper
Full-text available
Study on the synthesis and characterization nanosilica of tetraethylorthosilicate (TEOS) with the addition of polyethylene glycol (PEG) using sol-gel method has been done. Addition of PEG is used as a capping agent that aims to avoid the occurrence of agglomeration. Sol solution was added with PEG- 6000 solution with concentration of 10% and 15% (w / v). The mixed solution was evaporation with a temperature of 700C for 48 hours. The obtained crystals were crushed and calcination at 6000C for 2 hours. The resulting product was characterized to determine the effect of PEG-6000 (10%, and 15% (w / v)) variation on the mean particle size, morphology and distrbusi of the resulting nanosilica particles. The results that the typical absorption peak of SiO2 in all samples was the siloxane group (Si-O-Si) which was the typical peak of TEOS. The resulting morphology is amorph. The average particle size was 55.55 nm for Ns control, Ns-PEG 10% (43.72 nm), and Ns-PEG 15% (52.40 nm) and. The best average size distribution was Ns-PEG 10% with PdI value of 0, 73 which showed good uniformity and particle size 3,4 d.nm.
Article
Full-text available
The inhibitive action of extracts from Citrofortunella microcarpa (Calamansi) peels on mild steel in 1.0M HCl solution has been studied using the weight-loss method, electrochemical method, and SEM-EDX analysis. The measurements showed that calamansi peels have good inhibition properties. Weight loss results suggest that inhibitive efficiency increases as the concentration increases. It was also found that the adsorption stabilizes at 72 hours and degrades at longer immersion times. SEM studies of the immersed mild steel showed the decreasing extent of corrosion attack on mild steel at an increasing ratio of inhibitor, while EDX analysis shows the reduction of the formation of corrosion products, suggesting the formation of inhibitor film on the mild steel surface. The Calamansi peel extract inhibitor obeys the Langmuir adsorption isotherm model and the mode of adsorption was found to be physical and spontaneous. The results of the electrolysis technique have shown the favoring of inhibition in cathodic reactions.
Article
Sensory analysis is a key method to assess flavor quality and to characterize consumer preference and acceptance, whereas instrumental analysis helps to identify flavor compounds. The combination of sensory analysis and instrumental analysis provides a platform for revealing key flavor compounds associated with consumer liking. This review discusses sensory evaluation, aroma analysis, and separation techniques using coffee as a central theme where possible to explore the aforementioned techniques. Emerging statistical methodologies are discussed along with their role in tying together discrete studies to reveal important flavor compounds that are either positively or negatively associated with consumer liking. Coffee is very widely studied, a fact that may be partially ascribed to its immense popularity in modern society. To this end, more than 100 sensory lexicons have been developed and implemented to describe specific coffee characteristics and around 1,000 volatile compounds have been identified in coffee. As a remarkably complex sample coffee has provided substantial impetus for adoption of new analytical approaches such as multidimensional separation technologies. This review describes common and emerging analytical techniques that have been employed for coffee analysis, with a particular emphasis placed on those associated with determination of volatile compounds. A comprehensive list of volatile compounds reported in coffee from 1959–2014 is included herein.
Article
Kumquat and calamansi are two exotic citrus fruits that are integral in Asian cuisine. While they possess excellent flavour profiles and potential health benefits, they have not been as extensively studied as other citrus fruits. In this study, the peel oil extracts of four kumquats (Jindou, Youpi, Huapi and Suichuan) and two calamansis (the Philippines and Indonesia) were analysed using gas chromatography-mass spectrometry (GC/MS). Principal component analysis (PCA) revealed a distinct separation of kumquat and calamansi, with Huapi kumquat differentiated from the other three kumquats based on their volatile profiles. Subsequently, Youpi kumquat and Philippines calamansi were further selected for aroma extract dilution analysis (AEDA), revealing 36 and 34 key odourants, respectively. Linalool and β-pinene were the two major key odourants in Youpi kumquat, while limonene and linalool were determined to have the greatest contribution to the aroma of Philippines calamansi. With the aid of a GC coupled with a quadrupole time-of-flight MS (QTOF/MS) detector, indole was identified in Youpi kumquat and reported for the first time as a key odourant in kumquat. This study enriches existing knowledge of these exotic citrus fruits, allowing for further applications of these fruit aromas in flavour or perfumery.
Article
Citrus peel (CP), a by-product of the citrus fruit processing, comprises nearly forty to fifty percent of the fruit portion. Interestingly, the essential oil (EO) is primarily concentrated in the peel portion of the citrus fruit. Extraction of CP essential oil (CPEO) is an effective way of utilizing the citrus fruit processing waste. The CPEO can be more efficiently recovered from CP waste by improving the efficiency of conventional extraction processes. The main components of CPEO include monoterpenes, sesquiterpenes and their oxygenated derivatives. Specifically, limonene is the major oil component identified in the peel of different citrus species. The health promoting biological activities of CPEO are an antioxidant, anti-inflammatory, analgesic, antimicrobial and anticancer agents, thereby can be used as a source of functional components and preservatives for the development of nutritionally safe newer food products. This paper provides an in-depth knowledge about the chemical constituents and bioactivities of EOs extracted from peels of different citrus species.
Data
Full-text available
In summary, the canonical discriminant analysis: % - Transform the variables so that the pooled within-group covariance matrix is % an identity matrix. % - Compute group means on the transformed variables. % - Perform a principal component analysis on the means, weighting each mean by % the number of observations in the group. The eigenvalues are equal to the ratio % of between-group variation to the within-group variation in the direction of % each principal component. Here, the principal component analysis is runned by % the singular value decomposition. % - Back-transform the principal components into the space of the original variables, % obtaining the canonical variables. % %File gives you the option to get an unbiased or maximum-likelihood parameter estimation.
Article
Full-text available
A flexible method is needed for constrained ordination on the basis of any distance or dissimilarity measure, which will display a cloud of multivariate points by reference to a specific a priori hypothesis.We suggest the use of principal coordinate analysis (PCO, metric MDS), followed by either a canonical discriminant analysis (CDA, when the hypothesis concerns groups) or a canonical correlation analysis (CCorA, when the hypothesis concerns relationships with environmental or other variables), to provide a flexible and meaningful constrained ordination of ecological species abundance data. Called ‘‘CAP’’ for ‘‘Canonical Analysis of Principal coordinates,’’ this method will allow a constrained ordination to be done on the basis of any distance or dissimilarity measure. We describe CAP in detail, including how it can uncover patterns that are masked in an unconstrained MDS ordination. Canonical tests using permutations are also given, and we show how the method can be used (1) to place a new observation into the canonical space using only interpoint dissimilarities, (2) to classify observations and obtain misclassification or residual errors, and (3) to correlate the original variables with patterns on canonical plots. Misclassification error or residual error is used to obtain a non-arbitrary decision concerning the appropriate dimensionality of the response data cloud (number of PCO axes) for the ensuing canonical analysis. We suggest that a CAP ordination and an unconstrained ordination, such as MDS, together will provide important information for meaningful multivariate analyses of ecological data by reference to explicit a priori hypotheses.
Article
Full-text available
A common objective in commercial reforestation is to plant seedlings that will produce superior adult trees. Long forest management planning horizons and life spans of most forest trees complicate the prediction of growth and performance of adult trees originating from planted seedlings of unknown genetic origin. We used multivariate statistics to identify and rank a set of seedlings characteristics that could predict the performance of mature trees in Pinus ponderosa. Results indicated that metabolic heat rate (q), a measure of total metabolism, of one-year-old foliage during the peak growth in May, was the most important seedling characteristic that predicted mature-tree performance. Increased metabolic heat rate in seedlings corresponded with greater vigor of mature trees. Additionally, seedling basal stem diameter (D), height (H), and needle length (NL), measured in November, were, in order of importance, other variables that defined the vigor class of the mature clones. However, these seedling morphological characteristics correlated negatively with vigor classification of the mature clones, contradicting the notion that greater D and/or H during the seedling stage may indicate a greater vigor at maturity.
Article
Full-text available
The relative correlation of 52 aroma and 5 taste components in commercial not-from-concentrate grapefruit juices with flavor panel preference was determined. Methylene chloride extracts of juice were analyzed using GC/MS with a DB-5 column. Nonvolatiles determined included limonin and naringin by HPLC, degrees Brix, total acids, and degrees Brix/acid ratio. Juice samples were classified into low, medium, or high categories, based on average taste panel preference scores (nine-point hedonic scale). Principal component analysis demonstrated that highest quality juices were tightly clustered. Discriminant analysis indicated that 82% of the samples could be identified in the correct preference category using only myrcene, beta-caryophyllene, linalool, nootkatone, and degrees Brix. Nootkatone alone was not strongly associated with preference scores. The most preferred juices were strongly associated with low myrcene, low linalool, and intermediate levels of beta-caryophyllene.
Chapter
Chemometrics is “the use of computational and mathematical methods to extract information from analytical data” (Hibbert and James 1987). Advances in a chemist’s ability to make measurements of the nature and composition of essential oils has led to a potential bottleneck in obtaining the maximum information from the plethora of high-quality data that arises. It is now perfectly possible to measure the concentrations of hundreds of essential oils from a plant, and how these data are analysed is the concern of this chapter.
Article
A study was conducted in Michigan's Upper Peninsula to test the strength and weakness of canonical discriminant analysis (CDA) as a spectral transformation technique to separate ground scene classes which have close spectral signatures. Classification accuracies using CDA transformed images were compared to those using principal component analysis (PCA) transformed images. Results showed that Kappa accuracies using CDA images were significantly higher than those derived using PCA at α = 0.05. Comparison of CDA and PCA eigen structure matrices indicated that there is no distinct pattern in terms of source variable contributions and load signs between the canonical discriminant functions and the principal components.
Article
Cold-pressed oil (CPO) components from 8 varieties of pummelos were identified and measured. γ-Terpinene was the second major component in 4 varieties, but only a minor component in the others. Cadina-1(10), 6, 8-triene was identified by GC-MS in addition to the 63 compounds identified already. Multivariate analyses were applied to 37 kinds of citrus fruits including pummelos and other species. The pummelo was classified into 2 groups by cluster analysis, and into 3 groups by principal component analysis on the basis of the oxygenated composition (w/w%) in fresh CPOs. The tendency for classification agreed in the two analyses. Nootkatone was the only discriminating component of the pummelo species from others. The results are also discussed in citrus species other than pummelo, being compared with the botanical classifications.
Article
The chemical composition of the volatile compounds of peel and leaf oils from Calamondin (xCitrofortunella microcarpa (Bunge) Wijnands) was studied by GC and GC-MS. Fifty-nine and seventy-two compounds were identified, which represented nearly 100 % of the total composition of the peel oil and leaf oil. The chemical components of these oils showed marked differences in quantity as well as quality. The most prominent compounds in the peel oil was limonene (77.0 %), while in the leaf oil the major components were elemol (15.4 %) and α-eudesmol (11.1 %).
Article
Changes in 44 compounds of yuzu (Citrus junos Sieb. ex Tanaka) steam-distilled peel oil (SDO) and possible artifacts that accrue during storage at 25°C were investigated after 1, 2, 3, 4, 8 and 12 weeks. Changes in SDO composition during storage took place more rapidly than in cold-pressed oil. Total monoterpene hydrocarbons decreased markedly, with major losses of limonene and γ-terpinene and notable increases in p-cymene, as well as alcohols. Bicyclogermacrene, the main sesquiterpene hydrocarbon of the fresh oil, practically disappeared. (-)-Spathulenol, the main artifact, was converted from bicyclogermacrene. Antioxidants such as α-tocopherol, β-carotene and 2,6-di-tert-butyl-4-hydroxytoluene (BHT) slowed the formation of oxidation products, such as p-cymene, (-)-spathulenol by inhibiting the formation of oxidative products. This suggests that the antioxidants can be used to maintain yuzu oil quality.
Article
The application of three multivariate analysis techniques (canonical discriminant analysis (CDA), principal component analysis (PCA), and canonical correlation analysis (CCA)) for evaluation of pasture botanical composition data is illustrated and discussed. CDA and PCA were used to describe differences in pasture botanical composition for different microsites within a pasture near Palmerston North, New Zealand. CCA could not be validly applied to this data set because a sampling strategy inappropriate for CCA had been used to collect the data. However, CCA is conceptually ideal for determining association between two groups of variables and CCA was used for a second data set from the Hawkes Bay region to establish association between differences in pasture botanical composition and differences in environmental variables. CCA identified a transition from white clover (Trifolium repens L.) to subterranean clover {Trifolium subterraneum L.) presence associated with decreasing rainfall, and a similar transition from ryegrass presence to browntop presence associated with altitude. There are practical difficulties in obtaining a suitable data set for canonical correlation, but with attention to sampling strategy a more precise definition of effect of environmental factors on pasture botanical composition would be expected.
Article
This research was undertaken to determine the sugars, organic acids, phenolic compositions and antioxidant capacities of grapefruits (cvs. Rio red, Star ruby, Ruby red and Handerson) grown in Turkey. High-performance liquid chromatographic methods were used to identify and quantify three sugars (sucrose, glucose and fructose) and five organic acids (oxalic, citric, ascorbic, malic and succinic acids). The major organic acid was found as citric acid. With regard to sugars, sucrose was present in the largest amounts for grapefruit juices. The sum of sugars ranged from 75.81 to 85.43gL−1 and the sum of organic acids ranged from 22.50 to 26.78gL−1. A total of 15 phenolic compounds were identified and quantified in grapefruit juices, including hydroxybenzoic acids (4), hydroxycinnamic acids (5), and flavanones (6) compounds. Total phenolic content ranged from 441.09 (Ruby red) to 725.71mgL−1 (Star ruby) and antioxidant activity (AE) ranged from 34.51(Ruby red) to 128.37×10−3 (Star ruby).
Article
The volatile compounds of Citrus juices have been extracted by headspace solid-phase microextraction (HS-SPME) and analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). This work deals with the analysis of 65 cross pollinated hybrid fruits and their parents: mandarin (Citrus reticulata Blanco var. Willow Leaf) and clementine (Citrus reticulata×Citrus sinensis var. Commune). Among the 44 components identified which accounted for 90.2 to 99.8% of the volatile fraction, limonene (56.8–93.3%) and γ-terpinene (0.1–36.4%) were the major components in all samples. The clementine juice was characterised by the pre-eminence of limonene (90.0%) and a minor amount of γ-terpinene (1.2%) while the mandarin juice exhibited high amount of limonene (66.3%) and γ-terpinene (21.1%). All hybrid juices showed qualitatively similar composition but differing in the quantitative profile of the couple limonene/γ-terpinene. The principal component analysis (PCA) and the discriminant analysis indicated that hybrids samples were symmetrically distributed around the both parents. If some studies were found in the literature about mandarin juice, to our knowledge, this work is the first study on the volatile compounds of clementine juice and a large amount of hybrids.
Article
The volatile constituents of fresh calamondin (Citrus madurensis Lour.) cultivated in the Philippines were investigated by GC and GC/MS. As a result, 58 and 98 compounds were identified from the peel and juice volatile concentrates, respectively. The characteristic flavor components of calamondin were examined by GC-olfactometry. Limonene, cis-linalool oxide, linalool, α-terpineol, (E,E)-2,4-decadienal, and methyl N-methyl anthranilate had high flavor dilution factors. Additionally, the enantiomeric ratio of limonene, linalool, terpinen-4-ol and α-terpineol in calamondin were measured by chiral GC.
Article
A possible way to valorize citrus peels and seeds, which are byproducts of the juice extraction industry, is to use them as natural antioxidants. The antioxidant activity of several citrus peel and seed extracts obtained either by methanol extraction (free phenolic compounds) or by alkaline hydrolysis (bound phenolic compounds) was tested in a model system based on accelerated citronellal oxidation. Generally, seeds possessed greater antioxidant activity than peels. The composition of all tested samples was studied by HPLC:  methanol extracts are rich in flavones and glycosylated flavanones, whereas hydrolyzed extracts contain mainly phenolic acids and flavonols. The phenolic composition of some citrus peels and seeds was described for the first time. No clear relationship could be shown between the antioxidant activity and the phenolic composition of the extracts. Keywords: Citrus fruits; byproducts; antioxidant activity; flavanones; phenolic acids
Article
Calamondin peel oil extract from two composite peel samples with hexane were each analyzed by gas chromatography−mass spectrometry (GC−MS), and 56 constituents were identified and quantified by GC peak area percent values. All except 5 of these components had been identified previously in citrus juices or oils. Composition of the peel oil components most resembled that reported earlier for kumquat, a member of the Fortunella species believed to be one of the parents of calamondin. Keywords: Citrus; gas chromatography; mass spectrometry; flavor; peel essential oil
Article
The changes of 34 components constituting a relative 97.6% of the total volatiles of yuzu (Citrus junos Sieb. ex Tanaka) cold-pressed peel oil and the possible artifacts during storage at −21, 5, and 20 °C were investigated after 1, 3, 6, 9, and 12 months. Major qualitative changes were found after 12 months at 20 °C. Total monoterpene hydrocarbons underwent a large decrease (from 93.3 to 37.7%), with major loses of limonene, γ-terpinene, myrcene, and α-pinene, while notable increases occurred in p-cymene as well as the monoterpene alcohols (from 2.1 to 13.2%). Bicyclogermacrene, the main sesquiterpene hydrocarbon of the fresh oil (1.0%), was virtually depleted. Sesquiterpene alcohols were formed as dominant artifacts (36.1%) and constituted the second most abundant volatile group of the oil after the monoterpene hydrocarbons. (−)-Spathulenol (decahydro-1,1,7-trimethyl-4-methylene-1H-cyclopropylazulen-7-ol) was the main artifact among the 14 identified. The alcohol constituted the second major component of the oil after limonene from the ninth month and accounted for more than 75% of the sesquiterpenic alcohols at 20 °C. The spathulenol was found for the first time to be an artifact in yuzu oil. The compound could be a useful index for monitoring the quality and freshness of yuzu flavor during storage. Keywords: Citrus junos Sieb. ex Tanaka; cold-pressed oil; volatile component; storage time; storage temperature; relative composition; sesquiterpenes; artifact; spathulenol
Article
4-Vinylguaiacol (PVG), a major off-flavor in citrus products, was detected in stored model solutions of orange juice (MOJ) containing ferulic acid, and its amount increased with time and temperature. PVG was not found in MOJ incubated without ferulic acid. Vanillin, another ferulic acid degradation product, was also detected in MOJ containing ferulic acid after incubation at 35 and 45-degrees-C, but only minute amounts occurred at 25-degrees-C. Vanillin was not produced, however, in MOJ incubated with added PVG but which did not contain ferulic acid. Incubation of MOJ under nitrogen atmosphere rather than air or including butylated hydroxytoluene did not affect PVG levels even though nonenzymic browning products such as 5-(hydroxymethyl)furfural and furfural, and optical density values were reduced. Cu ions accelerated browning but decreased PVG levels. It appears that different factors affect PVG formation and sugar degradation.
Article
Free phenolic acids may be the precursors for vinyl phenols and off-flavours formed in citrus products during storage. Quantitative determination of free and bound phenolic acids in fruit parts of grapefruit (Citrus paradisi Macfadyen) and oranges (Citrus sinensis (L) Osbeck) was performed by extraction with ethyl acetate, silica gel column chromatography and HPLC analyses of samples before and after alkaline hydrolysis. The content of free and bound phenolic acids was further determined in juice derived from fruit harvested early, mid and late in season. As found previously for ferulic acid, phenolic acids occur mainly in bound forms in grapefruits and oranges. In both fruits the peels contained the major portion of cinnamic acids compared with the endocarp, and the flavedo was richer in hydroxycinnamic acids than the albedo. In most cases, hydroxycinnamic acid content was in the following order: ferulic acid>sinapic acid>coumaric acid>caffeic acid. Results showed that the content of bound cinnamic acids was unchanged or slightly elevated from early to late season. However, the content of free acids was reduced during that period.
Article
The compositions of Vietnamese pummelo (Citrus grandis Osbeck), orange (C. sinensis Osbeck), tangerine (C. reticulata Blanco var. tangerine) and lime (C. limonia Osbeck) peel oil samples have been investigated by GC and GC–MS. The essential oils were extracted by the cold-pressing method. Hydrocarbons, followed by aldehydes and alcohols, were the most abundant compounds in all four kinds of samples. Their percentages, respectively, were >98.7%, >97.6%, >98.6% and >95.4% in hydrocarbons; >0.3%, 0.4%, >0.3% and 1.1% in total aldehydes; 0.2%, 0.5%, 0.4% and 0.7% in alcohols. In Vietnamese pummelo oil, γ-terpinene was not detected, while terpinolene was detected in small amounts and nootkatone only at a level of <0.05%. Orange oil composition was comparable to that of other sweet orange oils. δ-3-Carene was detected at a level of 0.1%. Tangerine oil is easily distinguished from other citrus oils by its content of various aliphatic aldehydes. Lime oil presented a very different composition from the other oils studied. Its limonene content was substantially lower than that of pummelo, orange and tangerine oils, whereas γ-terpinene, β-pinene and α-pinene occurred in higher proportions, moreover, the sesquiterpene hydrocarbon fraction of this oil is qualitatively more complex and quantitatively more abundant than in the other oils. Copyright © 2002 John Wiley & Sons, Ltd.
Article
Leaves from 109 trees in 11 populations spanning the geographic range of Melaleuca alternifolia were analyzed for qualitative and quantitative variation in essential oils. Significant differences in oil yield were recorded between populations indicating the potential for improvement from a breeding program. Considerable variation in oil composition was found, both among and within populations, Trees from the northwestern populations produced a terpinolene-rich oil while eastern populations produced an oil with either terpinen-4-ol or 1,8-cineole as the major component. Differences in terpene composition among populations support data from allozyme analyses suggesting genetic differentiation of populations in the northwestern extremity of the species range. The study confirms three previously identified chemical forms in eastern populations and proposes recognition of two chemical forms in northwestern populations. Populations were identified with individuals suitable for inclusion in a breeding program.
Article
Composition and distribution of phenolic acids in Ponkan (Citrus poonensis Hort. ex Tanaka) and Huyou (Citrus paradisi Macf. Changshanhuyou) during maturity was investigated comprehensively in this study. High-performance liquid chromatography (HPLC) coupled with photodiode array (PDA) detector method was developed to separate and quantify protocatechuic, p-hydroxybenzoic, vanillic, caffeic, p-coumaric, ferulic, sinapic, and chlorogenic. For all of the phenolic acids, detection limits were about 0.01 μg/mL. Repeatability was 0.57–2.99% (relative standard deviation, RSD) for intraday and recovery ranged from 80.23% to 114.53%. In this study, phenolic acids were divided into four fractions: free, ester, glycoside and ester-bound. Generally, in each fraction, Ponkan had higher content of phenolic acids than Huyou, and with maturity there was a sharp decrease of them in both varieties, also peel contained more of them than flesh. Furthermore, chlorogenic acid and ferulic acid were the highest among the eight quantified phenolic acids, and content of caffeic acid was rather high at unripe stage, and hydroxycinnamic acids accounted for a larger portion compared with hydroxybenzoic acids especially for Ponkan. The total content of phenolic acids ranged from 180 μg/g DW (flesh of Huyou at ripe stage) to 5060 μg/g DW (peel of Ponkan at unripe stage). The data obtained here can be potentially used for discriminating the adulteration of citrus juices and may be useful for consumers and food technologists.
Article
The phenolic compounds and antioxidant capacities of orange juices obtained from cvs. Moro and Sanguinello (Citrus sinensis (L.) Osbeck) were determined. A high-performance liquid chromatographic method coupled with diode-array detection was used to identify and quantify phenolic compounds of the orange juices. A total of 18 phenolic compounds were identified and quantified in Moro and Sanguinello orange juices, including hydroxybenzoic acids (2), hydroxycinnamic acids (5), flavanones (5), and anthocyanins (6). It was observed that total phenolic content of Moro juice was higher than that of Sanguinello juice. Ferulic acid was the most dominant hydroxycinnamic acid and cyanidin 3-(6″-malonyl glucoside) and cyanidin 3-glucoside were the most dominant anthocyanins in both cultivars. Antioxidant activities of orange juices were measured using the DPPH· (2,2-diphenyl-1-picrylhydrazyl) method. According to DPPH· assays, the antioxidant capacity of Moro juice was found to be higher than that of Sanguinello juice.
Chapter
Apple pomace is the press cake resulting from pressing apples for juice (see Fig. 1). This chapter is not an all-encompassing review of apple pomace, but rather highlights areas the authors view as significant and with which they have expertise. Production figures for apple pomace are shown in Table 1.
Article
The essential oils of six different yuzu cultivars, Kumon (KUM), Nagano (NAG), Yasu (YAS), Jimoto (JIM), Komatsu Sadao (KOS) and Komatsu Koichi (KOK), were extracted by cold-pressing method. A total of 69 compounds of the six samples were identified. Application of GC-olfactometry and aroma extraction dilution analysis technique in three-fold stepwise dilution of the neat oil for all samples indicated eight odourants with the highest flavour dilution (FD) values. Those were limonene, α-pinene, α- and β-phellandrene, myrcene, γ-terpinene, (E)-β-farnesene and linalool. ‘KOS’ was differentiated from the other oil samples by showing the highest number of components having yuzu-like odour notes and also from the PCA analysis of the FD-factor values. This is the first time the aroma characteristics of yuzu essential oils of specified cultivars were investigated.
Article
Selective elimination of residual error can be used when applying Harrington's ANOVA-PCA in order to improve the capabilities of the method. ANOVA-PCA is sometimes unable to discriminate between levels of a factor when sources of high residual variability are present. In some cases this variability is not random, possesses some structure and is large enough to be responsible for the first principal components calculated by the PCA step in the ANOVA-PCA. This fact sometimes makes it impossible for the interesting variance to be in the first two PCA components. By using the proposed selective residuals elimination procedure, one may improve the ability of the method to detect significant factors as well as have an understanding of the different kinds of residual variance present in the data. Two datasets are used to show how the method is used in order to iteratively detect variance associated with the factors even when it is not initially visible. A permutation method is used to confirm that the observed significance of the factors was not accidental.
Article
Citrus juices are a complex mixture of flavor and taste components. Historically, the contributions of taste components such as sugar (sweet) and acid (sour) components were understood before impactful aroma volatiles because they existed at higher concentrations and could be measured with the technologies of the 1920s and 1930s. The advent of gas chromatography in the 1950s allowed citrus researchers to separate and tentatively identify the major citrus volatiles. Additional volatiles were identified when mass spectrometry was coupled to capillary GC. Unfortunately, the major citrus volatiles were not major influences of citrus flavor. The major aroma impact compounds were found at trace concentrations. With the advent of increasingly more sensitive instrumental techniques, juice sample size shrank from 2025 L in the 1920s to 10 mL today and detection limits fell from percent to micrograms per liter. Currently gas chromatography-olfactometry is the technique of choice to identify which volatiles in citrus juices possess aroma activity, determine their relative aroma strength, and characterize their aroma quality but does not indicate how they interact together or with the juice matrix. Flavor equations based primarily on nonvolatiles and other physical measurements have been largely unsuccessful. The most successful flavor prediction equations that employ instrumental concentration values are based on a combination of aroma active volatiles and degrees Brix (sugar) values.
Article
Typical flavour of Muscat d'Alexandrie wines is mainly due to volatile compounds coming from grapes of this variety. Therefore, the choice of grapes is crucial to obtain musts with a great aromatic potential, which will contribute to the final aroma of wines derived from those musts. In this study, three sampling techniques, liquid-liquid extraction (LLE), solid phase extraction (SPE) and simultaneous distillation-extraction (SDE), were compared for the analysis of volatile compounds in Muscat grape juice. Results showed that although the three techniques can be recommended for the quantitative analysis of volatile compounds from musts, LLE and SPE are better sample preparation techniques than SDE, mainly for determination of polar compounds such as acids or alcohols.
Article
Extraction, resolution, and determination of the trans-hydroxycinnamic acids (caffeic, p-coumaric, ferulic, and sinapic) were performed in 82 orange juices derived from the most important blood and blond varieties grown in Italy. Soluble solids, acidity, and anthocyanins were also determined. Hydroxycinnamic acids were more abundant in blood orange than in blond juices. Ferulic acid was the major component in all cases, but the distribution of the four acids was typical in each variety. Discriminant analysis of the experimental results showed that these acids could be used as markers of blood and blond varieties. The statistical model was used to recognize some mixtures of blood and blond juices.
Article
Extracts from the peel and flesh of a citrus fruit, dekopon (Shiranuhi mandarin Suppl. J.), were obtained under reduced pressure followed by dichloromethane extraction. A total of 127 volatile chemicals were identified in the extracts using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). They included 11 monoterpenes, 32 monoterpenoids, 9 sesquiterpenes, 5 sesquiterpenoids, 20 aliphatic alcohols, 14 aliphatic esters, 15 aliphatic aldehydes and ketones, 7 aliphatic acids, and 10 miscellaneous compounds. The major volatile constituents of the extract from the peel were d-limonene (2380.33 mg/kg), myrcene (36.54 mg/kg), bisabolene (30.03 mg/kg), sabinene (21.12 mg/kg), trans-beta-ocimene (16.96 mg/kg), valencene (12.84 mg/kg), decanal (8.14 mg/kg), beta-phellandrene (4.53 mg/kg), citronellol (4.51 mg/kg), 4-terpineol (4.50 mg/kg), linalool (4.13 mg/kg), and citronellyl acetate (3.63 mg/kg). The major volatile constituents of the extract from the flesh were ethyl acetate (21.54 mg/kg), acetoin (7.23 mg/kg), 3-methylbutanol (2.79 mg/kg), p-mentha-cis-2,8-dien-1-ol (1.01 mg/kg), 3-methylbutanoic acid (0.95 mg/kg), isobutanol (0.59 mg/kg), trans-isopiperitenol (0.58 mg/kg), p-mentha-trans-2,8-dien-1-ol, and trans-carveol (0.44 mg/kg). Compositions of volatile chemicals in peel and flesh extract were considerably different: the peel extract was rich in terpenes, whereas the flesh extract was rich in aliphatic compounds.
Article
The chemical changes and artifact formation in daidai (Citrus aurantium L. var. Cyathifera Y. Tanaka) cold-pressed peel oil upon storage at 20, 5, and -21 degrees C for 3, 6, and 12 months were investigated using capillary gas chromatography (GC) and GC-MS. Major changes occurred in the oil stored at 20 and 5 degrees C. No changes were found at -21 degrees C. Monoterpene hydrocarbons decreased from 98.0 to 66.4% upon 12 months at 20 degrees C, while sesquiterpene hydrocarbons and alcohols increased from 0.1 to 2.4% and from 0.3 to 7.9%, respectively. Notable decreases of germacrene D, myrcene, linalyl acetate, and limonene occurred. Prominent increases of cis-carveol, trans-beta-farnesene, trans-p-2,8-menthadien-1-ol, linalool, and beta-caryophyllene were found. Thirty-four artifact compounds constituting 17.0% of the total volatile compounds were formed upon 12 months at 20 degrees C. The artifacts consisted of 13 alcohols (6.0%), five carbonyl compounds (5.3%), seven esters (4.9%), three epoxides (0.4%), four hydrocarbons (0.3%), and two unidentified. The prominent artifact compounds were (+)-carvone, trans,trans-farnesyl acetate, sabinene hydrate, 1-octen-3-ol, cis,cis-farnesyl acetate, and dihydrocarveol acetate. The results could be applied for monitoring and control of the flavor quality of daidai essential oil and related products.
Flavor formation in fruits and vegetables
  • H B Heath
  • G Reineccius
Heath, H. B., & Reineccius, G. (2005). Flavor formation in fruits and vegetables. In Flavor chemistry and technology (3rd ed., pp. 73-101). Boca Raton, FL: CRC Press.
The oil composition of less common Citrus species
  • B M Lawrence
Lawrence, B. M. (2002). The oil composition of less common Citrus species. In G. Dugo & A. Di Giacomo (Eds.), Citrus-the genus Citrus (pp. 318-354). Boca Raton: Taylor & Francis.
A critical review on the chemical composition of citrus oil
  • M H Boelens
Boelens, M. H. (1991). A critical review on the chemical composition of citrus oil. Perfumer and Flavorist, 16, 17-34.
RAFisher2cda: Canonical disriminant analysis. A Matlab file. [WWW document]
  • A Trujillo-Ortiz
  • R Hernandez-Walls
  • S Perez-Osuna
Trujillo-Ortiz, A., Hernandez-Walls, R., & Perez-Osuna, S. (2004). RAFisher2cda: Canonical disriminant analysis. A Matlab file. [WWW document]. <http:// www.mathworks.com/matlabcentral/fileexchange/4836-rafisher2cda>.
Mandarin-like hybrids of recent interest for fresh consumption. Problems and ways of control. China/FAO Citrus symposium
  • A Nicotra
Nicotra, A. (2001). Mandarin-like hybrids of recent interest for fresh consumption. Problems and ways of control. China/FAO Citrus symposium.
Essential oil from the peels of Citrus macrocarpa
  • M C Nigam
  • D R Dhingra
  • G N Gupta
Nigam, M. C., Dhingra, D. R., & Gupta, G. N. (1958). Essential oil from the peels of Citrus macrocarpa Bunge. Indian Perfume, 2, 36-38.
Rutaceae, Citrus The encyclopedia of fruits & nuts
  • F G Gmitter
  • J Soneji
  • M Nageswara
  • S Huang
Gmitter, F. G., Soneji, J., Nageswara, M., & Huang, S. (2008). Rutaceae, Citrus. In J. Janick & R. E. Paull (Eds.), The encyclopedia of fruits & nuts (pp. 773–788).
Citrus fruit, biology, technology and evaluation
  • M Ladaniya
Ladaniya, M. (2008). Citrus fruit, biology, technology and evaluation. London: Academic Press.