Effects of hot water treatment on the essential oils of calamondin

Abstract

Essential oilVolatile a b s t r a c t 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 chromatographyeflame 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 b-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, a-terpineol, and carvone, the content of which were boosted by steam distillation. Whole fruit contained higher levels of monoterpene alcohols than peel did.

A comparison of volatile fractions obtained from Lonicera macranthoides via different extraction processes: ultrasound, microwave, Soxhlet extraction, hydrodistillation, and cold maceration

“…Additionally, CM always results in an odor similar to that in the original plant material without causing degradation of the thermo labile compounds present in the fraction due to the low extraction temperature similar to cold pressing, 24 rather than heating in HD or SE, which makes heating a factor investigated for extraction of volatile fractions from aromatic flowers. However, the exact differences about the volatile fractions extracted via the five methods mentioned above have not been reported yet.…”

Comparative assessment of volatiles in juices and essential oils from minor Citrus fruits (Rutaceae)

“…The Calamondin EO obtained by cold pressing was also different to that studied in Taipei, Taiwan ( Citrus microcarpa Bonge) where monoterpenes dominated with respect to the EO composition obtained by steam distillation; in our sample the percentage of this class of compounds was reversed. However, the sesquiterpenes found in the hand cold pressed EO (7.4%) were higher than those evidenced in the hydrodistilled EO (1.8%), probably because of the non‐distillation method which avoids heat stress 37 . The composition of the C x myrtifolia hand cold pressed EOs was reported here for the first time since no literature has been available until now on this topic.…”

“…However, the sesquiterpenes found in the hand cold pressed EO (7.4%) were higher than those evidenced in the hydrodistilled EO (1.8%), probably because of the non-distillation method which avoids heat stress. 37 The composition of the C x myrtifolia hand cold pressed EOs was reported here for the first time since no literature has been available until now on this topic.…”

Traditional Small-Size Citrus from Taiwan: Essential Oils, Bioactive Compounds and Antioxidant Capacity

“…Because terpenes themselves are light and heat sensitive, they are prone to deterioration during storage. Heat stress induces the oxidative degradation of limonene, resulting in the formation of monoterpene hydrocarbons or oxygenated monoterpenes [ 5 , 6 , 20 ]. The terpineol and carvone components are formed by the oxidative degradation of limonene and are well known for their contribution to the loss of flavor and quality of citrus juices.…”

“…As fresh fruits, they are sour to the taste, but both are widely used in processed fruit products, such as pickled preserves and marmalade. When fresh calamondin fruit is used with hot water to make beverages, there is some concern as to the resulting modifications of flavonoids and essential oils of the fruit [ 3 , 4 , 5 ]. Meanwhile, the peel of the kumquat is thin and full of flavonoids, and is edible along with the fruit flesh.…”