The chemistry and technology of cinnamon

Cinnamon (Cinnamomum zeylanicum, Nees in Wall) is one of the world's oldest spices. Sri Lanka is the main provider of cinnamon, mainly exported as “cinnamon quills.” From a phytochemical viewpoint, cinnamon is a uniquely interesting plant. The volatile oils obtained from the bark, leaf, and root bark vary significantly in chemical composition. Each oil has a different primary constituent: cinnamaldehyde (in the bark oil), eugenol (in the leaf oil), and camphor (in the root‐bark oil). Recent studies based on techniques such as gas‐liquid chromatography and infrared spectrometry have revealed that the three oils possess the same array of monoterpene hydrocarbons in different proportions. Both gas‐liquid chromatography and quantitative infrared spectrometry have recently been used to study changes in the chemical composition in the volatiles of cultivated and wild‐growing cinnamons. As a result, some interesting biosynthetic speculations have evolved, and reliable methods of analytical assessment of quality have been developed. The technology of production of cinnamon oils has varied little from the methods introduced by the early Dutch settlers. They are based on variations on the general theme of steam distillation. Recently, new still designs have greatly enhanced the technological capability in Sri Lanka. Cinnamon bark and leaf oils form the basis of a variety of synthetically derived chemicals used in the food and cosmetic industries.     

An integrated strategy to control post-harvest decay of Embul banana by combining essential oils with modified atmosphere packaging

Mature Embul (Musa, AAB) bananas were treated with emulsions of either cinnamon bark or leaf (Cinnamomum zeylanicum) or clove (Syzygium aromaticum) oils to control post‐harvest diseases, packed under modified atmosphere (MA) using low‐density polyethylene (0.075 mm, LDPE) bags, and stored in a cold room (14 ± 1 °C, 90% RH) or at ambient temperature (28 ± 2 °C). The effects of the essential oils on post‐harvest diseases; physico‐chemical properties and organoleptic properties were determined and compared with controls and bananas treated with benomyl. Treatments with cinnamon bark and leaf oils controlled crown rot, whereas clove oil treatment did not affect crown rot development. Treatment with emulsions of cinnamon oils combined with MA packaging can be recommended as a safe, cost‐effective method for extending the storage life of Embul bananas up to 21 days in a cold room and 14 days at 28 ± 2 °C without affecting the organoleptic and physico‐chemical properties.     

Chemistry, biogenesis, and biological activities of Cinnamomum zeylanicum

The genus Cinnamomum comprises of several hundreds of species, which are distributed in Asia and Australia. Cinnamomum zeylanicum, the source of cinnamon bark and leaf oils, is an indigenous tree of Sri Lanka, although most oil now comes from cultivated areas. C. zeylanicum is an important spice and aromatic crop having wide applications in flavoring, perfumery, beverages, and medicines. Volatile oils from different parts of cinnamon such as leaves, bark, fruits, root bark, flowers, and buds have been isolated by hydro distillation/steam distillation and supercritical fluid extraction. The chemical compositions of the volatile oils have been identified by GC and GC-MS. More than 80 compounds were identified from different parts of cinnamon. The leaf oil has a major component called eugenol. Cinnamaldehyde and camphor have been reported to be the major components of volatile oils from stem bark and root bark, respectively. Trans-cinnamyl acetate was found to be the major compound in fruits, flowers, and fruit stalks. These volatile oils were found to exhibit antioxidant, antimicrobial, and antidiabetic activities. C. zeylanicum bark and fruits were found to contain proanthocyandins with doubly linked bis-flavan-3-ol units in the molecule. The present review provides a coherent presentation of scattered literature on the chemistry, biogenesis, and biological activities of cinnamon.     

Comparative study of the essential oils of three Beilschmiedia species and their biological activities

This study was designed to examine the chemical compositions of the essential oils from three Beilschmiedia species and antioxidant, antimicrobial, antityrosinase, acetylcholinesterase and anti‐inflammatory activities. The essential oils of B. kunstleri, B. maingayi, B. penangiana gave β‐caryophyllene (10.6–12.1%), β‐eudesmol (17.5–24.1%) and δ‐cadinene (17.5–28.7%) as the most abundant components respectively. The bark oil of B. maingayi showed the highest activity in β‐carotene/linoleic acid (125.9%) and phenolic content (288.2 mg GA g^?1), while B. penangiana bark oil was found to have strong activity in DPPH (IC₅₀ 84.7 μg mL^?1) and ABTS (IC₅₀ 108.3 μg mL^?1). The essential oils of B. penangiana showed the best activity against Candida glabrata with MIC value 31.3 μg mL^?1. The bark oil of B. penangiana gave 82.5% tyrosinase inhibiton. The leaf oil of B. maingayi gave the highest inhibition in AChE (66.6%) and lipoxygenase (77.0%) assay. Our findings demonstrate that the essential oils have great potential for applications in pharmaceutical and food industries.     

Properties of Cassava Starch‐Based Edible Coating Containing Essential Oils

Edible coatings were produced using cassava starch (2% and 3% w/v) containing cinnamon bark (0.05% to 0.30% v/v) or fennel (0.05% to 0.30% v/v) essential oils. Edible cassava starch coating at 2% and 3% (w/v) containing or not containing 0.30% (v/v) of each essential oils conferred increased in water vapor resistance and decreased in the respiration rates of coated apple slices when compared with uncoated fruit. Cassava starch coatings (2% w/v) added 0.10% or 0.30% (v/v) fennel or cinnamon bark essential oils showed antioxidant capacity, and the addition of 0.30% (v/v) of each essential oil demonstrated antimicrobial properties. The coating containing cinnamon bark essential oil showed a significant antioxidant capacity, comparing to fennel essential oil. Antimicrobial tests showed that the addition of 0.30% (v/v) cinnamon bark essential oil to the edible coating inhibited the growth of Staphylococcus aureus and Salmonella choleraesuis, and 0.30% fennel essential oil inhibited just S. aureus. Treatment with 2% (w/v) of cassava starch containing 0.30% (v/v) of the cinnamon bark essential oil showed barrier properties, an antioxidant capacity and microbial inhibition.     

Oxidative Stability of Cooking Oil Blend Stabilized with Leaf Extract of Eucalyptus citriodora

The present study was conducted to assess the effects of Eucalyptus citriodora (E. citriodora) leaf extract on the oxidative stability of blend of canola, rapeseed, and sunflower oils (45:20:35 v/v, respectively) under accelerated storage. The blended oil was stabilized with 300 mg/L ethanolic extract (source of total phenolic content and total flavonoid content [5.23 ± 0.19 and 1.18 ± 0.04 g/100 g d.wt. of extract]) of E. citriodora leaves. The oxidative stability was measured on the basis of parameters such as free fatty acid contents, peroxide value, sponification value, iodine value, color, cloud point, and refractive index. After a 100 day incubation period, the increase in refractive index, free fatty acid, and peroxide, and sponification values in stabilized and non-stabilized oil blends were 0.0028 and 0.0047, 0.20 and 2.37% as oleic acid, 12.54 and 21.12 meq/kg of oil and 10.04 and 17.01 meq of KOH/g of oil, respectively, as compared with initial values. However, a decrease of 10.0 and 16.9 g of iodine/100 g of oil was recorded in oil iodine values of both stabilized and non-stabilized blended vegetable oils. Results showed that E. citriodora leaf extract was found effective to maintain the oxidative stability of blended vegetable oils for long duration (6 months) as compared with control oil samples. Therefore, it can be concluded that E. citriodora leaf extract is a cheap rich source of natural antioxidants that can be easily used for the stabilization of vegetable oils in the food processing industries.     

Photoxidation of Cinnamon Oil

Commercial cinnamon leaf oil and bark oil distillates from commercially ground cinnamon were oxidized via immobilized riboflavin at 22°C under 1740 lumens of light in a model system. Most components of bark oil were oxidized in the model system which produced singlet oxygen. Compound disappearance was observed in cinnamon bark oil distillates with storage time of ground cinnamon. Bleached and filtered cinnamon leaf oil was resistant to oxidation in the model system. Thirty-seven water-soluble compounds in bark distillate were identified using GUMS procedures. Of these compounds 10 had not been previously reported in the literature.     

French Fries oleuropein content during the successive deep frying in oils enriched with an olive leaf extract

Olive oil, sunflower oil and soybean oil were enriched with an olive (Olea Europaea) leaf extract rich in oleuropein at a supplementation level of 100 mg total phenolics per kg oil. Supplemented oils were used for deep frying of potatoes for eight successive frying sessions without replenishment under domestic frying conditions. Supplemented oils contained oleuropein while deep frying resulted in a gradual decrease in oils oleuropein content. After the eighth successive frying, oleuropein was still detected in oils, its retention being 3.2–12.4%. Deep frying of potatoes in supplemented oils succeeded in preparing French fries containing oleuropein even after eight successive fryings. Contrary to the oil type, the number of frying sessions affected potatoes oleuropein content. Oleuropein intake by consuming French fries deep‐fried in enriched oils was approximately ten times higher in potatoes prepared in the first frying session as compared to the respective intake after the eighth frying.     

Chemical composition,antibacterial and antioxidant activity of the essential oils of Metaplexis japonica and their antibacterial components

The aim of this research was to determine the chemical composition, antioxidant and antibacterial properties of the essential oils from Metaplexis japonica and isolation of antibacterial constituents from the essential oils. Results showed that 63 components were identified in essential oils. Phenylethyl alcohol (77.978%), α‐terpineol (31.810%) and docosane (21.644%) were the most abundent constituents of flower oil, leaf oil and fruit oil, respectively. Based on bioactivity‐guided fractionation, three active constituents were isolated and identified as phenylethyl alcohol, α‐terpineol and β‐linalool. Both flower oil and phenylethyl alcohol showed high antibacterial performance, with inhibition zone from 25 ± 0.5 to 11 ± 0.6 mm at highest concentration, and MIC values ranging from 0.125 to 2%. In both DPPH and ABTS assay, the oils showed moderate antioxidant activity. These results indicate potential efficacy of active constituents and essential oils of M. japonica to control food‐borne pathogenic and spoilage bacteria.     

TITRIMETRIC DETERMINATION OF TOTAL ALDEHYDES IN CINNAMON BARK AND LEAF OILS USING CHLORAMINE-T REAGENT

A titrimetric method for determining cinnamaldehyde has been developed; it is based on the quantitative reaction of the aldehyde with semicarbazide hydrochloride to form the semicarbazone. The semicarbazone is removed and the excess unreacted semicarbazide determined iodometrically using chloramine-T reagent. Two moles of chloramine-T are required per mole of the semicarbazide. The method has been used in the routine quality evaluation of cinnamon oils and the samples required are about 0.02 g for bark oils and 0.05 g for leaf oils.     

Biological,medicinal and toxicological significance of Eucalyptus leaf essential oil: a review

The genus Eucalyptus L'Heritier comprises about 900 species, of which more than 300 species contain volatile essential oil in their leaves. About 20 species, within these, have a high content of 1,8‐cineole (more than 70%), commercially used for the production of essential oils in the pharmaceutical and cosmetic industries. However, Eucalyptus is extensively planted for pulp, plywood and solid wood production, but its leaf aromatic oil has astounding widespread biological activities, including antimicrobial, antiseptic, antioxidant, chemotherapeutic, respiratory and gastrointestinal disorder treatment, wound healing, and insecticidal/insect repellent, herbicidal, acaricidal, nematicidal, and perfumes, soap making and grease remover. In the present review, we have made an attempt to congregate the biological ingredients of leaf essential oil, leaf oil as a natural medicine, and pharmacological and toxicological values of the leaf oil of different Eucalyptus species worldwide. © 2017 Society of Chemical Industry     

Phenolic compounds of the genus pyrus. VI. Distribution of phenols amongst the various tissues of the pyrus stem

Stems of Pyrus calleryana, P. ussuriensis and P. communis var. jaspoideae, from both current and previous year's growth, were sampled in January and March and the phenols in the bud, cork, green cortex, white phloem and xylem tissues were investigated. For the individual tissues there appeared to be very little difference between the phenols of current and previous year's growth. However, although some phenols, such as arbutin and vanilloylcalleryanin, occur throughout all tissues of both January and March stems at about the same concentrations, certain other phenols tend to accumulate in particular tissues at particular times. The flavonoid glycosides, for example, were found in the buds, cork and green cortex, generally at markedly lower levels than in the leaves, but were absent from the white phloem and xylem. A comparison between leaf and whole bark (i.e. cork + green cortex + white phloem) of all available Pyrus species has shown that the bark phenols are generally more restricted in range than the leaf phenols and that no new phenols, hitherto undetected in the leaf, are to be found in the bark. Caffeoylcalleryanin and catechins are more obvious as bark rather than leaf constituents; as a leaf constituent, caffeoylcalleryanin has a somewhat limited distribution within Pyrus but as a bark constituent it is almost ubiquitous.     

Antimicrobial Efficacy of an Array of Essential Oils Against Lactic Acid Bacteria

The essential oils of clove bud, cinnamon bark and thyme, and their individual compounds including allyl isothiocyanate (AIT), carvacrol, cinnamaldehyde, cinnamic acid, eugenol, and thymol were initially assessed for antimicrobial activity against 9 lactic acid bacteria (LAB) species. Carvacrol and thymol were the most inhibitory with MICs of 0.1% (v/v and w/v, respectively). Cinnamaldehyde, cinnamon bark oil, clove bud oil, eugenol, and thyme oil were moderately inhibitive (MICs = 0.2% v/v), while cinnamic acid required a concentration of 0.5% (w/v). AIT was not effective with MICs in excess of concentrations tested (0.75% v/v). The bactericidal capability of the oil components carvacrol, cinnamaldehyde, eugenol, and thymol were further examined against Pediococcus acidilactici, Lactobacillus buchneri, and Leuconostoc citrovorum. Thymol at 0.1% (w/v) was bactericidal against L. citrovorum (>4‐log reduction), but resulted in a 2‐log CFU/mL reduction against L. buchneri and P. acidilactici. Cinnamaldehyde at 0.2% to 0.25% (v/v) was effective against L. citrovorum, L. buchneri, and P. acidilactici, resulting in a >2‐log reduction. All 3 organisms were susceptible to 0.2% carvacrol with >3‐log reduction observed after exposure for 6 h. Eugenol was the least effective. Concentrations of 0.2% and 0.25% (v/v) were needed to achieve an initial reduction in population, >3‐log CFU/mL after 6 h exposure. However, at 0.2%, P. acidilactici and L. buchneri recovered to initial populations in 48 to 72 h. Results indicate essential oils have the capacity to inactivate LAB that are commonly associated with spoilage of shelf stable low‐acid foods.     

Influence of polar compounds distribution in deep-frying oil on lipid digestion behaviour

Deep-frying oil featuring total polar compound (TPC) has been found to be unhealthy. However, little information is available regarding the impact of TPC on the lipid digestion behaviour. In this study, three typical edible oils (palm oil, PO; high oleic acid peanut oil, HOA; and high linoleic acid sunflower oil, HLA) were selected to investigate the effect of deep-frying on the lipid digestion. Digestion behaviour was monitored by pH-Stat method in vitro. Digestibility rate analysis showed that free fatty acids release rate of all TPC groups was the slowest among corresponding fresh oils and deep-frying oils, indicating deep-frying decreased lipid digestion rate. Lipid droplet analysis uncovered that deep-frying could increase lipid particle size. Correlation analysis showed the polymers in TPC are negatively correlated with digestion rate and particle size, suggesting the digestion behaviour of deep-frying oil is related to TPC constitution. In conclusion, this study highlights that deep-frying weaken the lipid digestion capacity, and the multiplicity of TPC distribution which vary in terms of FAs type contribute to differences of digestion behaviour in deep-frying oils.     

Chemical diversity in curry leaf (Murraya koenigii) essential oils

Wild and cultivated Murraya koenigii leaf essential oils collected from ten Indian locations were investigated for their chemical diversity. The essential oil yields ranged from 1.2–2.5 ml/kg biomass. GC and GC-MS analyses revealed ninety compounds, constituting 93.8–99.9% of the essential oils. The highest concentrations of α-pinene (55.7%) and β-pinene (10.6%) were found in the essential oil of wild plants. α-Pinene (13.5–35.7%) and/or β-phellandrene (14.7–50.2%) were the dominant essential oil constituents of seven locations. (E)-Caryophyllene (26.5%, 31.5%) and α-selinene (9.5%, 10.4%) were the principal essential oil components of two locations. The odour profiles of the essential oils were distinctly different. Tetradecanoic acid, hexadecanoic acid, piperitone, cada-1,4-diene,1,10-di-epi-cubenol, γ-eudesmol, α-muurolol, (Z,E)-farnesol and (Z,Z)-farnesol are identified for the first time in curry leaf essential oil. The chemical diversity of the oils offers opportunity to flavourists to choose curry leaves and essential oils with preferential flavour composition.     

Physicochemical properties,total phenol and tocopherol of some Acacia seed oils

BACKGROUND: Recently, there has been an increase in the number of investigations into the possible use of vegetable oils as a source of oleochemicals to supplement petrochemicals. We have therefore determined the physicochemical properties of Acacia oils and compared them with groundnut oil as a first step toward their possible industrial utilization. RESULTS: The chemical properties of Acacia oils compared well and surpassed those of groundnut oil in iodine value (1549.3, 1783.3 and 1093.1 g iodine kg^?1 oil for A. colei, A. tumida and groundnut oils, respectively), saponification value (201.74, 202.15 and 198.01 g KOH kg^?1 oil for A. colei, A. tumida and groundnut oils, respectively). Total phenol and tocopherol content of Acacia oils were also higher compared with groundnut oil. Refractive index, specific gravity and viscosity were higher in Acacia seed oils than in groundnut oil but the smoke point of Acacia oil was lower than that of groundnut oil. Acacia oils were higher in some essential elements (Mg, Ca, Fe, Zn and Cu) when compare with groundnut oil. CONCLUSION: The properties of Acacia oils revealed that they could be useful as drying oils, in soap making and as lubricants at low temperatures. They could also be dietary sources of natural antioxidants and essential elements. Copyright © 2007 Society of Chemical Industry     

Pigment profile and colour of monovarietal virgin olive oils from Arbequina cultivar obtained during two consecutive crop seasons

Monovarietal virgin olive oils are labelled with the olive varieties giving them their distinctive character. There are numerous studies focussed on the characterisation and quantification of the minor fractions of virgin olive oils that have generated databases on varietal olive oils. However, few studies have focussed on the components of the pigment fraction of virgin olive oils. The aim of this work was to quantify the components of the chlorophyll and carotenoid fractions of the monovarietal virgin olive oils from the Arbequina cultivar, growing in the Spanish area of Catalonia, during two consecutive crop seasons. Additionally the pigment changes occurring during 24 months of oil storage were evaluated. The results of this study showed minor qualitative differences between monovarietal virgin olive oils from two consecutive seasons. The quantitative differences could be attributed to the harvest period in each season rather than to the year’s weather conditions. Storage of the monovarietal virgin olive oils probably caused an important loss of the chlorophyll fraction, mainly chlorophyll a, during the first 6 months of storage. On the other hand, the carotenoid fraction was very stable and the retention of provitamin A was close to 80%, even after 24 months of storage.     

Characteristics and antioxidant activity of leaf essential oil–incorporated fish gelatin films as affected by surfactants

Characteristics of film from fish skin gelatin incorporated with four leaf essential oils (lemongrass, basil, citronella and kaffir lime), as influenced by different surfactants (Tween‐20, Tween‐80 and soy lecithin), were investigated. Films incorporated with all essential oils had lower tensile strength with higher elongation at break and thickness, compared with control film (P < 0.05). Films added with Tween‐20 showed higher TS, compared with those containing other surfactants (P < 0.05). Water vapour permeability of films incorporated with all essential oils markedly decreased in comparison with control (P < 0.05). Films generally became darker and more yellowness, when incorporated with essential oils. Film containing basil essential oil had the highest DPPH radical– and ABTS radical–scavenging activities, compared with those added with other essential oils. Higher antioxidative activity was obtained in films containing essential oils when soy lecithin was used as surfactant, probably due to the combined effect of both constituents.     

Identification and Detection of Adulterated Camellia Oleifera Abel. Oils by Near Infrared Transmittance Spectroscopy

Under the serious circumstances of Camellia oleifera adulteration, the accurate examination for quality trait of C. oleifera oil is extremely urgent. The use of near infrared transmittance spectroscopy as a rapid and cost-efficient classification technique for the authentication of Camellia oil was investigated. At the same time, the feasibility of near infrared transmittance spectroscopy for the rapid determination of soybean oil and maize oil adulterated in binary and ternary system Camellia oils was explored. The results showed that identifications was made based on the slight difference in raw near infrared transmittance spectra in Camellia oils, soybean oils, maize oils, and those adulterated with soybean and maize oil with discriminant equations techniques. Furthermore, the performance of near infrared transmittance spectroscopy models for binary and ternary system adulterated Camellia oils was satisfactory. Moreover, the near infrared transmittance spectroscopy calibration model of soybean oil (0–50%) in binary system adulterated Camellia oils was the best, and correlation coefficients of the cross-validation (R_cv) was 0.99999. For the near infrared transmittance spectroscopy calibration model of maize oil in binary system (0–50%) and ternary system (0–40%) adulterated Camellia oils, the R_cv were 0.99996 and 0.99961, respectively. In addition, the coefficients of external validation for three models were obtained (0.9998, 0.9999, and 0.9967, respectively). In all, near infrared transmittance spectroscopy could be conducted to identify Camellia oils and detect soybean oil and maize oil adulterated in binary and ternay system Camellia oils from the methodology.     

Microsatellite markers to identify specific alleles in DNA extracted from monovarietal virgin olive oils

The suitability of DNA present in olive oil for PCR analysis has been reported by several authors. However, low concentration, degradation, and the possible presence of additional alleles due to paternal contribution in oils extracted from entire drupes, should be taken into consideration when comparing the amplification profiles of leaves with the corresponding oils for varietal traceability purposes. The aim of this work was to assess, by capillary electrophoresis of microsatellite markers, the phenetic relationships among seven certified Olea europaea L. cultivars, and to verify the genomic equality between leaf DNA and the corresponding monovarietal oil DNA. Moreover, the aim was to establish an identification key to distinguish all the types of oil among them with the minimum number of markers. The results referred to oil DNA, obtained in 70 PCR experiments, confirmed the possibility, in 85.7% of cases, of extracting DNA suitable for the analysis of microsatellites. Ninety percent of the successful amplifications led to identical patterns for leaves and oil DNA. Cima di Melfi shared only 20% of the alleles with the other cultivars. Toscanina and Leccino, showed the highest similarity (about 60%). A single microsatellite was able to distinguish the seven types of oil.