Rind Oil Research Articles

Biological Activities of Papaya (Carica papaya L.) Seed, Rind and Pulp Oil Extracts

Background: Carica Papaya L. is widely cultivated for food and traditional medicine throughout the World due to its rich source of bioactive compounds in its fruit, leaves, latex and stem. Objective: The aim of this work was to assess the physicochemical properties, and antioxidant and antimicrobial activities of oils extracted from papaya seeds, fruit pulp and rind using the solvent ex-traction method. Methods: Hexane mediated extraction of oil was made. Then, physicochemical properties of the oil extracts were based on the determination of oil yield, specific gravity, acid value, free fatty acid and peroxide value, while the antioxidant activities were conducted based on ascorbic acid content, DPPH and hydrogen peroxide free radical scavenging activities. The antimicrobial experiment was conducted based on disc diffusion and broth dilution methods. Results: The result of physicochemical properties of papaya seeds, pulp and rind oil extracts demon-strated significantly the highest oil yield (42.50%) and specific gravity (0.85) obtained for seed oil. Significantly the highest DPPH (19.35%), and hydrogen peroxide scavenging activities (32.45%) were recorded for seed oil extract. The strongest antibacterial activity with maximum zone of inhibition (18.50 mm), minimum inhibitory concentration MIC (0.03 μg/mL) and minimum bactericidal concen-tration MBC (0.05 μg/mL) were recorded for seed oil extract against S. pyogenes. However, the strong-est antifungal activity with maximum zone of inhibition (16.75 mm), MIC (0.05 μg/mL) and MFC (0.10 μg/mL) against C. albicans was recorded for rind oil extract against C. albicans. Conclusion: It can be concluded from the result of this study that seed oil was found to have antioxidant and antibacterial potential but fruit rind oil extract was the most effective antifungal in papaya.

Non-destructive Storage Time Prediction of Newhall Navel Oranges Based on the Characteristics of Rind Oil Glands.

How to non-destructively and quickly estimate the storage time of citrus fruit is necessary and urgent for freshness control in the fruit market. As a feasibility study, we present a non-destructive method for storage time prediction of Newhall navel oranges by investigating the characteristics of the rind oil glands in this paper. Through the observation using a digital microscope, the oil glands were divided into three types and the change of their proportions could indicate the rind status as well as the storage time. Images of the rind of the oranges were taken in intervals of 10 days for 40 days, and they were used to train and test the proposed prediction models based on K-Nearest Neighbors (KNN) and deep learning algorithms, respectively. The KNN-based model demonstrated explicit features for storage time prediction based on the gland characteristics and reached a high accuracy of 93.0%, and the deep learning-based model attained an even higher accuracy of 96.0% due to its strong adaptability and robustness. The workflow presented can be readily replicated to develop non-destructive methods to predict the storage time of other types of citrus fruit with similar oil gland characteristics in different storage conditions featuring high efficiency and accuracy.

Kinetics of Moisture Loss and Oil Absorption of Pork Rinds during Deep-Fat, Microwave-Assisted and Vacuum Frying.

The fat content of fried pork rinds is high, and alternative frying helps reduce the oil content and maintain their texture and taste. Different frying methods such as microwave-assisted, traditional deep frying and vacuum frying on the breaking force, color, microstructure, water loss and oil absorption attributes of fried pork rinds were evaluated in this study. The fat content of microwave-assisted and vacuum-fried pork rinds was lower (24.2 g/100 g dry weight basis (db) and 17.1 g/100 g db, respectively) than that (35.6 g/100 g db) of traditional deep-fat frying. Non-uniform, holy and irregular surface microstructures were obtained by vacuum frying due to rapid mass transfer at low pressure. The first-order kinetic models of water loss and oil absorption of traditional and microwave-assisted frying of pork rinds were established. Microwave frying caused a faster moisture loss rate, shorter frying time and lower pork rind oil content, makes it an attractive substitute for traditional deep-fat frying.

Modulation of tolerance of “Hamlin” sweet orange grown on three rootstocks to on-tree oleocellosis by summer plant water balance supply

Abstract Citrus fruit is prone to on-tree oleocellosis (OTO), which decreases its fresh market value due to deterioration in the fruit peel. This study aimed to evaluate the effects of Lichi16-6 trifoliata (Poncircus trifoliate, LC), Goutoucheng sour orange (Citrus aurantium, GT), and Rangpur lime (C. limonia Osbeck, RL) rootstocks on the occurrence of OTO, plant water status, reactive oxygen species (ROS) scavenging capacity of 12-year-old “Hamlin” sweet orange (C. sinensis Osbeck) trees in both 2014 and 2015 cropping seasons. The results showed that “Hamlin” trees grown on RL maintained higher water potential and relative water content (RWC) in leaves and fruit peels as well as higher transpiration in the morning and afternoon compared with scions grown on the other two rootstocks. This improved water status in the morning resulted in a lower diurnal range of rind oil release pressure (ΔRORP) and the incidence of OTO per tree (IOPT). However, although “Hamlin” trees grown on GT had a significantly higher transpiration in the morning, leaves of “Hamlin” trees grown on GT had the lowest transpiration in the afternoon compared with those grown on the other two rootstocks. This exacerbated water status in the afternoon resulted in higher malondialdehyde and ROS in leaves and severity of OTO per tree (SOPT). In conclusion, the tolerance of “Hamlin” sweet orange grown on three rootstocks to OTO was modulated by plant water balance supply during OTO-sensitive stage. Also, the ΔRORP and ROS scavenging capacity could be selected as indicators to assess IOPT and SOPT, respectively.

Role of Ca2+ and calmodulin in on-tree oleocellosis tolerance of Newhall navel orange

Previous studies have shown that spraying calcium on the canopy can significantly reduce the incidence of on-tree oleocellosis (OTO). However, the OTO regulation with calcium spraying has not been reported clearly. Therefore, the physiologic mechanism of spraying Ca(NO3)2 and calmodulin (CaM) inhibitors (trifluoperazine-TFP) on the canopy of 8-year-old Newhall navel orange on Lichi16-6 trifoliata (P. trifoliate) including the ratio (RO) and degree of OTO (DO) have been studied under high summer temperature. The results showed that exogenous Ca(NO3)2 treatment significantly decreased DO value by increase in CaM content of leaves, peroxidase (POD) activity in leaves, and fruit peels. However, TFP treatment significantly decreased CaM content in leaves, SOD and CAT activity in fruit peels, while the POD activity in fruit peels significantly increased, and the formation of Ca(NO3)2-induced DO tolerance in citrus fruits was weakened by TFP treatment. Exogenous Ca(NO3)2 treatment increased stomatal conductance (Gs) and transpiration rate (Tr), and decreased the daily range of rind oil release pressure (△RORP) significantly. However, TFP treatment had no significant influence on transpiration rate (Tr) and △RORP. The results were consistent with the RO of different treatments. These results confirm that Ca2+ and CaM regulate DO value, and the RO of OTO was mainly related to the regulation of △RORP through water metabolism.

Chemical composition and biological activities of rhizome and fruit rind oils of Alpinia mutica from south India

Volatile oils from dry rhizomes and fruit rinds of Alpinia mutica were isolated and characterized by GC-FID and GC-MS. A. mutica rhizome oil showed forty-seven components of which forty (92.8%) were characterized, and the major components were β-pinene (20.2%), camphor (13.3%), 1,8-cineole (8.9%), camphene (7.9%) and α-pinene (6.2%). Fruit rind essential oil showed sixty-nine components of which sixty-three (97.8%) were identified. Major constituents in A. mutica fruit rind oil were 1,8-cineole (14.8%), camphor (11.7%), β-pinene (7.6%) and camphene (4.8%). Four major constituents in both A. mutica rhizome and fruit rind oils (camphene, β-pinene, 1,8-cineole, camphor) were estimated by external standardization. Refractive index, specific rotation and specific gravity of both volatile oils were determined. Fruit rind oil showed significant antioxidant, cytotoxic and moderate antimicrobial activities. A. mutica dry fruit rind oil has a very pleasant smell with potential applications in fragrances.

Mid-Infrared Features of Kaolinite-Dickite

AbstractTransformation of kaolinite to dickite is a common diagenetic reaction. The present report is part of a wider study to investigate the pathways of this polytype change. Fourier-transform infrared spectroscopy (FTIR) was used to attempt quantification of the relative proportions of kaolinite and dickite, validated by X-ray diffraction (XRD) results, in order to link mineral and structural features during the mineralogical changes. A group of kaolinite and dickite samples was investigated: 13 samples from the Frøy and Rind oil fields (North Sea), three kaolinite specimens with different crystal order and particle size (KGa-2, kaolinite API 17, Keokuk kaolinite), and two dickite-rich samples (Natural History Museum collection). Six FTIR spectral features were analyzed: (1) intensity ratio of the minima at 3675 and 3635 cm−1; (2) position of the band at ~1115 cm−1; (3) difference between the frequency of the bands at ~1030 and ~1000 cm−1; (4) intensity ratio of the bands generating shoulders at ~922 and ~900 cm−1; (5) position of the band at ~370 cm−1; and (6) intensity of the band at ~268 cm−1. Correlation of the features above with polytype relative proportions derived from XRD showed non-linear behavior, with maximum curvature at the dickite end, which precludes kaolinite-dickite quantification. Increasing kaolin particle size is known to cause decreased intensity of the FTIR spectra. A model was developed to test whether this effect is consistent with the non-linear progression of the IR features. The relative intensity of kaolinite and dickite IR features were calculated in a series of kaolinite-to-dickite transformations, where the size of particles increases with dickite proportion, and where dickite-dominated particles reach a larger size than kaolinite-dominated particles. The results indicated that the differential particle size increase is possibly the cause of the lack of linearity between IR- and XRD-measured dickite proportions.

Kaolinite transformation into dickite during burial diagenesis

The mechanism of kaolinite transformation into dickite has been investigating using 13 samples from the Frøy and Rind oil fields (Broad Fourteens basin, North Sea), 3 kaolinite specimens with different crystal order (KGa-2, Kaolinite API 17, Keokuk kaolinite), and 2 dickite-rich samples (Natural History Museum collection). Detailed analysis of XRD, thermal analysis, and SEM data show that: (1) as dickite content increases, there is also an increase of the crystal order of kaolinite; (2) in dickite-rich specimens kaolinite and dickite have crystals (or XRD-coherent domains) of the same size; (3) there is no specific dehydroxylation temperature for each polytype, rather particle size and crystal order control dehydroxylation temperature independently of polytype; (4) with progressive dickite content, the development of both particle size and the size of the coherent crystal domains within particles is greater in the c direction than in the a - b plane; (5) the growth of defect-free segments in the c direction is not connected with the growth in the a and b directions, as would be expected in crystallization from solution; (6) textural features indicate coalescence of kaolin plates with burial; (7) there is a very weak positive correlation between particle dimensions and relative kaolinite-dickite content. These results are interpreted as resulting from a double reaction taking place in the solid state with burial. Some kaolinite domains grow in size and crystal order while other domains are transformed into dickite. Presumably, also the dickite domains formed early in the transformation grow in crystal order. The transformation into dickite stops at 90-95% dickite because the remaining kaolinite domains are so large and stable that the stability increase produced by the polytype transformation would be negligible.

Chemical Compositions and Biological Activities of Amomum subulatum Essential Oils from Nepal

The essential oils from the seed and rind of Amomum subulatum Roxb. (collected from Nepal) were obtained by hydrodistillation and analyzed by GC-MS. A total of 87 components were identified among the two essential oils accounting for 99.1%, and 99.0% of the oils, respectively. The two essential oils were dominated by the monoterpenoids 1,8-cineole (60.8% and 39.0%), alpha-pinene (6.4% and 4.8%), beta-pinene (8.3% and 17.7%), and alpha-terpineol (9.8% and 12.3%). Allelopathic testing of the seed essential oil showed an inhibition of seed germination of Lactuca sativa and Lolium perenne, with IC50 values of 1583 and 1674 microg/mL, respectively. The seed essential oil demonstrated a stronger seedling growth inhibition of L. perenne than of L. sativa. A. subulatum seed and rind oils also showed moderate brine shrimp lethality (LC50 = 28.1 +/- 3.0 and 15.0 +/- 9.0 microg/mL, respectively). The seed and rind oils were only marginally cytotoxic (20% and 30%% kill on MCF-7 cells at 100 microg/mL, respectively), and antibacterial (MIC > or = 313 microg/mL), but A. subulatum rind oil was appreciably active against the fungus Aspergillus niger (MIC = 19.5 microg/mL). The essential oils of A. subulatum were also screened for nematocidal activity against Caenorhabditis elegans and insecticidal activity against the fruit fly (Drosophila melanogaster) and the red imported fire ant (Solenopsis invicta x richteri). The seed oil was only marginally toxic to the fire ant (LC50 = 1500 microg/mL), but moderately toxic to the nematode and the fruit fly (LC50 = 341 and 441 microg/mL, respectively).

FACTORS AFFECTING RIND OIL CONTENT OF LEMON [CITRUS LIMON (L.) BURM. F.

Among the controllable and non-controllable factors affecting rind oil content of lemons, genetic (scion, rootstock) and environmental (growing conditions, canopy microclimate) factors play the most important role. 'Limoneira 8A', followed by 'Cicily', 'Lisbon' and 'Genoa' had the highest rind oil content, whereas 'Villafranca', 'Messina' and 'Yen Ben Lisbon' had the lowest. Rind oil content of 'Eureka' lemon was disappointingly low. Seedless cultivars, 'Eureka SL' and 'Lisbon SL', had ~18.0% higher rind oil content than the seeded cultivars from which they were derived. Fruit from lemon trees budded on non-invigorating rootstocks, e.g. X639 (a Cleopatra mandarin × Trifoliate orange hybrid), had the highest rind oil content, whereas rind oil content was low on invigorating rootstocks, e.g. rough lemon. South Africa has a diverse climate, and rind oil content from fruit produced in a hot, arid growing region (Upington) had the highest rind oil content, whereas fruit from relatively warm regions (Malelane and Marble Hall) ranked second, and rind oil content of fruit from a cooler region (Karino) was intermediate. Rind oil content from a cold growing region (Vaalharts) was the lowest. Regression analysis between rind oil content and cumulative heat units revealed a positive linear relationship, and in general, rind oil content increased with increasing heat unit accumulation. Following the sampling of fruit from different positions in a tree's canopy, light exposure was found to affect rind oil content of 'Eureka' lemon fruit. Fruit borne on the outside of trees, higher in the tree, north-facing or not within the hedgerow had the highest rind oil content. PAR data supports the hypothesis that rind oil content is correlated with light exposure. Therefore, the choice of scion cultivar and rootstock in a given growing region, together with judicious pruning to optimise light penetration into a tree’s canopy, contribute to enhanced rind oil yields.

Comparative efficacy of sweet orange, <i>Citrus sinensis</i>(l) rind powder and oil for the control of maize weevil, <i>Sitophilus zeamais</i> (motschulsky).

Sweet orange, Citrus sinensis((L.) rind powder and oil were evaluated for the control of maize weevil, Sitophilus zeamais(Mot.) under ambient laboratory conditions (28 ± 2o C and 75 ± 20% R.H.). Experiments consisted of exposing adult S. zeamais to both the powder and oil for 42 days. Mortality counts were taken from the first day after treatment (DAT) until 42 DAT. The result indicated that pulverized orange rind had no significant mortality effect on adult S. zeamais (P≥0.05) resulting in severe damage of the grains and weight loss. The Weevil Perforation Index (WPI) for all the dosages of the powder was greater than 50%, indicating reduced protectant effect; while the rind oil treatment resulted in significant mortality of adult S. zeamais (P≤ 0.05). There was significant reduction of grain damage when protected with oil extract. The WPI of all the dosages was below 50%, which confirmed the efficacy of the orange rind oil. The C. sinensis rind oil, not the powder can therefore be used for the storage of maize grains.Agro-Science Vol. 7 (1) 2008: pp. 9-14

Taxonomical contribution of essential oils in mandarins cultivars

Rind oils of nine cultivars of mandarin originated by recent mutation (Loretina, Marisol, Arrufatina, Clemenules, Clemenpons, Hernandina, Oronules, Satsuma Okitsu, Satsuma Owari) belonging to the Citrus reticulata Blanco species and 2 hybrids Fortune ( Citrus tangerine Hort. ex Tan x Citrus clementina Hort ex Tan) and Nova (Tangelo Orlando x Citrus clementina Hort ex Tan) were obtained from ripe fruits of trees growing in the same environmental and cultivated conditions. The study of their chemical composition was carried out by capillary GC, GC/MS and the results were submitted to discriminant analysis. The first discriminant function separates the α-thujene chemocultivar, corresponding to oriental mandarin cultivars (Satsuma Okitsu, Satsuma Owari), from the Mediterranean cultivars. Inside this last group, the second discriminant function split up the sabinene chemocultivar (Marisol, Arrufatina Clemenpons and Loretina from the hybrids group (Fortuna and Nova) and alters (Clemenules and Hernandina)). The differential compounds of these groups are: α-thujene α-pinene, sabinene, myrcene, limonene, linalool, α-terpineol and germacrene-D.

Structural basis of the rind disorder oleocellosis in Washington navel orange (Citrus sinensis L. Osbeck).

Oleocellosis, a physiological rind disorder of citrus fruit, is an unattractive surface blemish caused by phytotoxic effects of released rind oils. The development of oleocellosis in Washington navel orange (Citrus sinensis L. Osbeck) was examined by following a time sequence of surface symptoms and microscopic rind changes. The two natural causes of oleocellosis were simulated: mechanical damage to the fruit and transfer of rind oil between fruit. Mechanical fruit injury resulted in rupture of the epidermis above oil glands. Released surface oil appeared to infiltrate the rind via the ruptured epidermis resulting in rapid degeneration of cortical, but not epidermal, cell contents. Oil application to the rind surface produced a more severe blemish than did mechanical damage. The oil appeared to diffuse through the cuticle causing degeneration of the contents of all cell layers, including the epidermis. Loss of membrane integrity was detected within 30 min, followed by cell content degeneration and cell collapse. The resulting blemish, characterized by rind collapse and darkening, developed substantially within 3 d and was attributed to the cellular damage.

Cryo-SEM study of the early symptoms of peteca in `Lisbon’ lemons

SummaryEarly symptoms of the rind disorder peteca in ‘Lisbon’ lemons were investigated by cryo-SEM. The localized discoloration of the rind was associated with the albedo tissue. Oil glands showed varying amounts of oil contained within the oil gland cavity. In peteca-affected areas, rind oil was observed in the intercellular air spaces between the columns of epithelial cells forming the periphery of the gland and large amounts of oil accumulated in the albedo tissue. Ca levels were higher (ca. 23%) and B levels were lower (ca. 30%) in peteca-affected rind regions compared with unaffected rind regions of affected fruit. A considerable part of the Ca accumulated in the rind was in the form of Ca crystals, probably oxalate. The evidence for Ca oxalate deposition in rind tissue as a possible causal factor in peteca is reviewed.

Seasonal Variation in Lemon (Citrus limon L. Burm. f) Leaf and Rind Oil Composition

Volatile leaf oils of the Lupe strain of Lisbon lemon were analyzed by GC at monthly intervals from April 1993 through April 1994, respectively. Forty-seven lemon leaf oil components were identified by GC and GC-MS. In the leaf oils, the monoterpene limonene was die largest component (29–38%) followed by geranial (10–14%), β-pinene (9–18%), neral (5–10%), nerol (1–13%), sabinene (4–6%), geraniol (1–6%), and β-caryophyllene (2–4%). Monoterpenes were present at a higher percentage than the sesquiterpenes. It was found that the yield and composition of the volatile oils changed significantly during ripening. Plant to plant variation was in most cases statistically non-significant. Highest oil yields (370 mg/100g fw) were observed from leaves sampled in the month of December. Monoterpene hydrocarbons were higher in the beginning of the season and then decreased with time. Sesquiterpene hydrocarbons were less abundant in the beginning, but gradually increased during ripening

New method for quantitatively assessing susceptibility of citrus fruit to oleocellosis development and some factors that affect its expression

Summary. A quantitative laboratory method for determining the susceptibility of citrus fruit to oleocellosis (rind oil damage) has been developed. This method allows the evaluation of various factors which govern the extent of rind oil damage to the rind. By using this method, it has been established that the development of oleocellosis symptoms was affected by temperature, with temperatures <10˚C reducing the rate of development of the disorder. Unfortunately, when the temperature was raised again after storage, oleocellosis development proceeded as normal. Other environmental factors such as oxygen and carbon dioxide concentrations were also shown to affect the rate and extent of colour development of the rind blemish. This method of determining sensitivity of citrus peel to rind oil also established that the degree of surface exposure to sunlight increased the rind’s susceptibility to the oil. The effects of different coatings and chemicals which may affect the toxicity of the rind oils were also investigated, with artificial wax coatings being shown to reduce oil damage by up to 35%. This finding indicates the importance of thorough wax application to fruit. The tape method of sensitivity testing, as illustrated in this paper, also demonstrates that variations in oleocellosis development are not only due to changes in the pressure required to break the oil glands but also the ability of the peel to tolerate the released oil.

Characterisation of sour orange (Citrus aurantium) cultivars

AbstractTwenty‐one cultivars of sour orange (Citrus aurantium L) and relatives selected in different areas of Spain were studied. Morphological determinations were carried out both in leaves and in fruits, including leaf size and area, number of oil glands, petiole length, fruit weight, number of seeds and others. Biochemical analysis included electrophoretic separations of proteins from leaves and fruit rind as well as peroxidases and esterases from some of the organs. Also chromatographic separations of rind oils were carried out in mature fruits. Quantitative and qualitative differences were detected for some of the cultivars. Enzyme differences were found to be adequate for distinction at the specific level. Two of the cultivars, ‘Bergamot’ and ‘Amargo clementino’, segregate from the main group, which indicates their belonging to a different species or to a hybrid. The validity of the present determinations for distinction and characterisation of material to be included in a citrus germplasm bank is discussed.

Rind spot, antioxidative activity and tocopherols in the flavedo of citrus fruits

SummaryAntioxidative properties of Citrus junos and Citrus unshiu flavedo were investigated in relation to rind spot. In C. junos the flavedo with natural rind spot had less antioxidative activity than that of the sound flavedo. The strong activity in the sound C. unshiu flavedo appeared in the eluate fractionated with n- hexane where the antioxidant was not identified, α- and γ- tocopherols were quantified by high-performance liquid chromatography. There was a great difference in the ratio of γ-tocopherol to the total between sound and rind spot flavedos. The tocopherol concentrations were decreased by rind oil treatment despite the absence of disorder of the C. unshiu flavedo.

Rind spot and ascorbic acid in the flavedo of citrus fruits

SummaryAscorbic acid was investigated in the flavedo of Citrus junos, C. reticulata cv F-2428 and C. unshiu in connection with rind spot seen in citrus fruits on the tree at the ripening stage. Total ascorbic acid contents were 252, 165 and 229 mg l00g−1 in the sound flavedo of C. junos, C. reticulata and C. unshiu respectively. The ratio of dehydroascorbic acid to total ascorbic acid in the flavedo increased two- to threefold in flavedo with rind spot compared with sound flavedo. Similarly it increased in the flavedo of fruit with an artificial disorder resembling rind spot, induced by treatment with rind oils and some of their compounds. These data suggest that rind oil may be one of the causes of rind spot and may also be related to the oxidation of ascorbic acid around oil cells.

Effects of rind oils and their components on the induction of rind spot in citrus species

SummaryRind oil spot was investigated in seven species of citrus fruit while growing on the tree at the ripening stage. The disorder was artificially induced by rind oils and their components and there were differences in the responses of the different species. Rind oils induced rind spot in most species, as did linalool and rf-limonene, but Early Satsuma mandarin was barely susceptible. There were also differences in natural susceptibility to rind spot; the most susceptible species was C.junos, and the least was Early Satsuma mandarin (C. utishiu).