Studies on Essential Oil Composition of Cultivars of Black Pepper (Piper nigrum L.) - V

Journal of Essential Oil Research: JEOR, Mar/Apr 2005 by Menon, A Nirmala, Padmakumari, K P

Abstract

Two major cultivars of black pepper from Kerala viz. Vellanamban and Sreekara and one Indonesian cultivar grown in Kutching in Kerala were analyzed for a period of three consecutive seasons for their oil composition. Fifty-five compounds were identified in the oils by GC and GC/MS. The main components of vellanamban oil were sabinene (3.9-18.8%), β-pinene (3.9-10.9%), limonene (8.3-19.8%) and β-caryophyllene (28.4-32.9%). Sreekara oil contained as major compounds β-pinene (0-11.2%), limonene (20.1-22.1%) and β-caryophyllene (16.8-23.1 %). Kutching oil contained α-pinene(2.3-5.4%), sabinene (6.7-13.3%), limonene (14.5-17.5%) and β-caryophyllene (20.8-39.1%).

Key Word Index

Piper nigrum, Piperaceae, black pepper cultivars, essential oil composition, myrcene, β-pinene, sabinene, limonene, β-caryophyllene, elemol.

Introduction

Pepper is the most widely used spice throughout the world and so it is aptly called the 'king of spices.' The unique aroma of the spice has been studied by various workers (1-5), still it is an interesting spice to work upon for many throughout the world. The presence of mint sulfide and germacrene D in black pepper oil was reported by Takahashi et al. (6). Volatile compounds responsible for the distinct aroma and off flavor of black pepper and white pepper were studied by Jagella et al. (7). The presence of m-mentha-3(8),6-diene(isosylveterpinolene) in the black pepper and green pepper oil (0.12-0.17%) was detected by Nussbaumer et al. (8).Casablanca and Graff determined the enantiomeric distribution of linalool, δ-3-carene, limonene and α-thujene in pepper oil (9). Mollenbeck et al. analyzed Madagascar pepper oil by GC and GC//MS and identified 12 compounds and enantiomeric distribution of α-thujene and δ-3-carene. Korany and Amtmann analyzed the oils from Brazilian (Ampro), Indonesian (Lampong, SungaiBudi), Malaysian (Sarawak), Vietnamese (Saigon) black pepper and white pepper (Muntok, Sarawak)(10) and identified 16 compounds. Jagella and Grosch determined the key odorants of black pepper and white pepper and identified the musty/moldy flavor giving compound in black pepper as 2,3diethyl-5-methyl pyrazine and 2-isopropyl-3-methoxy pyrazine (11). They also found that the off odor/fecal odor associated with white pepper is due to skatole (11). Even though pepper oil was studied and more than 130 compounds were identified, the individual cultivar oils were not studied in detail. Richard et al. (9) analyzed 17 cultivars for their oil composition and identified 28 components. Lampong and Sarawak cultivars were analyzed for volatile compositional differences by Russel et al. (10). Sumathy et al. (11) studied Karimunda and Kalluvally cultivars for their proximate composition and volatile oil composition. Gopalakrishnan et al. (12) studied four selected cultivars of pepper and identified 67 compounds by GC/MS and retention indices. We studied the oils of 16 prominent cultivars viz: Karimunda, Kalluvally, Arakulammunda, Vellanamban, Kottanadan, Ottaplackal, Kuthiravally Cheriakaniakadan, Thevanmundi, Poonjaranmunda, Valiakaniakadan, Subhakara, Aimpiriyan, Narayakodi, Neelamundi and Uthirankotta for three seasons (13-15) and identified 55 compounds and their seasonal variations. The present paper reports the oil composition of yet another set of three major cultivars of black pepper. The cultivars selected for this study are Sreekara, Vellanamban and one Indonesian cultivar Kutching grown in Kerala. These cultivars are commonly cultivated in the northern parts of Kerala. To the best of our knowledge, no work has been carried out so far on their oil compositions by GC and GC/MS.

Experimental

The fresh berries of the authenticated cultivars were collected from Indian Institute of Spices Research, Calicut and were dried in a cross flow drier at 45°C and taken for the analysis. Moisture, starch, pipeline, crude fibre, ash and volatile oil were determined as per A.O.A.C methods. The volatile oil was analyzed for oil composition by GC and GC/MS.

GC: Gas chromatographic analyses were carried out in a Hewlett Packard gas chromatograph, model 5890-II GC equipped with electronic integrators. Carbowax and Methyl silicon columns were used (50 m x 0.2 mm, 0.17 µm) for the analyses. The conditions were as follows: temperature programming from 80-200°C, hold at 80°C for 1 min and at 200°C for 20 min, F.I.D. temperature 300°C, injection temperature 250°C, carrier gas: nitrogen at a flow rate of 1 mL/min, split ratio of 1:75.

GC/MS: GC/MS analyses were carried out in a Hewlett Packard gas chromatograph under the following conditions. GC conditions were the same as in the capillary GC analyses. MS conditions were as follows: electron impact, ionizing voltage 70 eV, source temperature 150°C, electron multiplier at 2000 eV, scan speed 690 amu/s and scan range 40-500 amu. Component identifications were accomplished by comparing retention indices and mass spectra of each compound with those of authentic samples and library, and literature (15-18).