Herbal distillate

Herbal distillates, also known as floral waters, flower waters, hydrosols, hydrolates, herbal waters, and essential waters, are aqueous products of hydrodistillation. They are colloidal suspensions of essential oils as well as water-soluble components obtained by steam distillation or hydrodistillation (a variant of steam distillation) from plants and herbs. These herbal distillates have uses as flavorings and cosmetics. Common herbal distillates for skincare include rose water, orange flower water, and witch hazel. Rosemary,[1] oregano, and thyme[2] are hydrosols that may be used in food manufacturing industries.

Production

Herbal distillates are produced in the same or similar manner as essential oils. However, essential oils will float to the top of the distillate where it can be removed, leaving behind the watery distillate. For this reason, the term essential water is an apt description. In the past, these essential waters were often considered a byproduct of distillation, but are now considered an important co-product.[3] The produced herbal waters are essentially diluted essential oils at less than 1% concentration (typically 0.02% to 0.05%).[4] Several factors, such as temperature and a herb's growth cycle, impact the characteristics of a distillate, and therefore influence the timing of the distillation. Rosemary, for example, should be distilled in the peak of summer before it flowers.[5]

Usage

Herbal distillates may be used in culinary applications to add subtle flavors to foods and beverages. Commonly used distillates in this context include rose water, orange blossom water, and peppermint hydrosol. Herbal distillates are used to preserve food, as by reducing the degree of oxidation of some meats.[6]

In the cosmetic industry, herbal distillates are used in facial cleansers, body mists, and air fresheners. Certain hydrosols can be used in steam inhalations. They are employed in traditional medicine.

Herbal distillates are used as insecticides, herbicides, and antibacterial and antifungal agents in agriculture. Additionally, herbal distillates may be used in allelopathy, with possible applications including the manipulation of the timing of sprouting (see vivipary) and germination.[6]

Science

The science of distillation is based on the fact that different substances evaporate at different temperatures. Unlike other extraction techniques based on solubility of a compound in either water or oil, distillation separates components regardless of their solubility. The plant material is distilled with water, in a form of steam distillation where the non-boiling plant essential oil is carried over by steam from boiling water, and is then condensed. Compounds with a higher vaporization point remain behind, and include water-soluble plant pigments and flavonoids.[7]

Because hydrosols are produced at high temperatures and are somewhat acidic, they tend to inhibit bacterial growth but not fungal growth. They are not sterile, and should be kept refrigerated to preserve freshness.[8] Herbal distillates degrade over time and will degrade faster than essential oils, which are more stable.[9] Small-scale producers of hydrosols must be particularly aware of the risk of bacterial contamination and take steps to prevent it. Despite concerns that there may be significant amounts of heavy metals in some herbal distillates, this has not shown to be the case.[10]

See also

  • Orange flower water
  • Rose water
  • Witch hazel (astringent)

References

  1. Christopoulou, Spyridoula D.; Androutsopoulou, Chrysa; Hahalis, Panagiotis; Kotsalou, Chrysoula; Vantarakis, Apostolos; Lamari, Fotini N. (18 December 2021). "Rosemary Extract and Essential Oil as Drink Ingredients: An Evaluation of Their Chemical Composition, Genotoxicity, Antimicrobial, Antiviral, and Antioxidant Properties". Foods. 10 (12): 3143. doi:10.3390/foods10123143. ISSN 2304-8158. PMC 8700793. PMID 34945695.
  2. Nieto, Gema (30 July 2020). "A Review on Applications and Uses of Thymus in the Food Industry". Plants. 9 (8): 961. Bibcode:2020Plnts...9..961N. doi:10.3390/plants9080961. ISSN 2223-7747. PMC 7464319. PMID 32751488.
  3. Risner, Derrick; Shayevitz, Avi; Haapala, Karl; Meunier-Goddik, Lisbeth; Hughes, Paul (1 April 2018). "Fermentation and distillation of cheese whey: Carbon dioxide-equivalent emissions and water use in the production of whey spirits and white whiskey". Journal of Dairy Science. 101 (4): 2963–2973. doi:10.3168/jds.2017-13774. ISSN 0022-0302. PMID 29398017.
  4. National Association for Holistic Aromatherapy. What are Hydrosols. Accessed 12-5-13
  5. Mulvaney, Jill (September 2012). "Traditional hydrosols and hydro-distillation". Australian Journal of Herbal Medicine. 24: 101–103.
  6. 1 2 Bolouri, Parisa; Salami, Robab; Kouhi, Shaghayegh; Kordi, Masoumeh; Asgari Lajayer, Behnam; Hadian, Javad; Astatkie, Tess (January 2022). "Applications of Essential Oils and Plant Extracts in Different Industries". Molecules. 27 (24): 8999. doi:10.3390/molecules27248999. ISSN 1420-3049. PMC 9781695. PMID 36558132.
  7. Tanaka, Yoshikazu; Sasaki, Nobuhiro; Ohmiya, Akemi (4 May 2008). "Biosynthesis of plant pigments: anthocyanins, betalains and carotenoids". The Plant Journal: For Cell and Molecular Biology. 54 (4): 733–749. doi:10.1111/j.1365-313X.2008.03447.x. ISSN 1365-313X. PMID 18476875.
  8. Jones, Cindy. "Herbal Waters or Distillates (Hydrosols)". Sagescript Institute. Archived from the original on 28 October 2006. Retrieved 23 October 2006.
  9. Garneau, François-Xavier; Collin, Guy; Gagnon, Hélène (June 2014). "Chemical composition and stability of hydrosols obtained during essential oil production. II. The case of Picea glauca (Moench) Voss., Solidago puberula Nutt., and Mentha piperita" (PDF). American Journal of Essential Oils and Natural Products. 1: 29–35.
  10. Keshtkar, Mozhgan; Dobaradaran, Sina; Soleimani, Farshid; Karbasdehi, Vahid Noroozi; Mohammadi, Mohammad Javad; Mirahmadi, Roghayeh; Ghasemi, Fatemeh Faraji (1 September 2016). "Data on heavy metals and selected anions in the Persian popular herbal distillates". Data in Brief. 8: 21–25. Bibcode:2016DIB.....8...21K. doi:10.1016/j.dib.2016.05.005. ISSN 2352-3409. PMC 4885015. PMID 27274526.

Books

  • Firth, Grace. Secrets of the Still. Epm Pubns Inc; First edition (June 1983)
  • Price, Len and Price, Shirley. Understanding Hydrolats: The Specific Hydrosols for Aromatherapy: A Guide for Health Professional. Churchill Livingstone 2004
  • Rose, Jeanne. 375 Essential Oils & Hydrosols. Frog, Ltd, Berkeley, CA, 1999. ISBN 1-883319-89-7
  • Rose, Jeanne. Hydrosols & Aromatic Waters. Institute of Aromatic & Herbal Study, 2007.