FLAVOUR AND FRAGRANCE JOURNAL, VOL. 9,89-91 (1994)

Book Reviews

NEWER TRENDS IN ESSENTIAL OILS AND FLAVOURS, edited by K. L. Dhar, R. K. Thappa and S. G. Aganval, Tata McGraw-Hill, New Delhi, 1993. No. of pages: xii + 376. ISBN 0-074620744.

This book is made up of selected papers presented at the International Symposium on Newer Trends in Essential Oils and Flavours, ISNTEOF-91, Jammu Tawi, India, 21-23 October 1991, and contains three plenary lectures and sixteen special lectures. The first plenary lecture, by Professor Sukh Dev (New Delhi), on ‘Pines to sandalwood’, outlines the synthesis of molecules with sandalwood aroma from car-3-ene, the main component of Indian turpentine. The second plenary lecture was by Professor Peter Weyerstahl (Berlin) on ‘New constituents from some north-west Indian Artemisia oils: analysis and synthesis’. The de- tails of some of this work has been reported in this journal. The third plenary lecture, ‘Stereocontrolled total syntheses of two antimalarial sesquiterpene per- oxides: qinghaosu and yingzhaosu A’, was by Professor Wei-Shan Zhou (Shanghai).

Among the special lectures, Akhtar Husain discus- ses ‘Present and future of agrotechnology of essential oil plants in India’. Although attempts are being made to introduce new crops, the export of essential oils overall is declining, owing to the decrease in the export of lemongrass and sandalwood oils. Sarin et al. review the ‘Aromatic flora of Himalayan Region-prospects of commercial utilisation’. To-day only five or six species have large-scale production, but the exploitation of four new species (Artemisia vestita, Ferula jaeschkeana, Skimmia laureola and the berries of a Cinnanomum sp.) looks promising. These authors exclude ‘Indian pine oleoresin gums-turpentine oils of indigenous pines’, which were well covered by Mehra and Dwiveda. NguyCii Xuan Dung et al. describe ‘Recent develop- ments on study of new sources of essential oils and flavours from Vietnam’, which include a new source of trans-methyl anethole from the leaves of Artemisia schmidtii. Bandyopadhyay discusses ‘Recent trends in flavour evaluation of spices’ in a general way. ‘Bio- synthetic studies of some isoprenoid compounds of perfumery and flavour values from the plants cultivated in CIMAP’ (Central Institute of Medicinal and Aro- matic Plants, Lucknow) are reported by Thakur and Akhila. Here the incorporation of labelled C 0 2 , meva- lonate, geraniol, nerol and farnesol into essential oil

constituents of at least ten plants is described. Chopra and Soma1 review the ‘Scope of biotransformation in essential oils’. Of the many transformations reported only the conversion of valencen into nootkatone appears to be commercially useful.

Several lectures dealt with the genetic improvement of essential oil plants. Sharma outlines how this may be achieved by repeated clone selection, cloline breeding, synthetic breeding, polypoidy breeding, mutation breeding, interspecific hybridization and cellular breed- ing and lists 34 improved clones so obtained. Kaul details the use of mutation breeding (X- and y-rays) to obtain improved clones of Mentha and Cymbopogon spp. while Rao et al. describe a new hybrid of Cymbopogon-CKP 25-which produces up to 400 kg oil per year per hectare which is a rich source of citral. Further, Sethi discusses ‘Genetic diversity and im- provement through hybridization in Palmarosa’ (C. martini var. ‘motia’). Pushpangadan emphasizes the importance and need for conservation of genetic re- sources of aromatic plants, especially in tropical and subtropical forests where unknown species may be lost in clearing. Pareek et al. describe ‘Recent advances in improving vetiver cultivation in India’. Starting with the new ‘Hybrid-8’, they investigated planting methods and plant density, fertilizer use, irrigation, intercrop- ping and stage of harvest.

‘Supercritical fluid extraction and separation of essential oils from botanicals’ was reviewed by Kumar et al., who described the extraction of ajowan seeds and costus root with C02. In the penultimate chapter, Shar- ma discusses ‘The utilization of essential oils and some common allelochemic constituents for non-insecticidal pest management strategies’. Of the 400 plant species surveyed, enriched extracts from the neem tree and the new herbal cyclopcide GWINCIL seem the most prom- ising. Finally Nijjar discusses ‘Optimising efficiency of energy balance (Calandria-type) distillation stills’. Over 2500 such stills, usually taking a 2-ton charge of (mint) herb, are now working in the Indian subconti- nent.

Overall these symposium papers provide a useful insight into recent developments and the state of the essential oil industry in India today. As such it can be recommended to readers of this journal.

ROGER STEVENS Threlkeld