Natural hickory smoke concentrate (Carya spp.)

Description
• Flavoring preparation obtained by controlled pyrolysis of hickory hardwood, followed by smoke capture, aqueous condensation, and fractionation to remove tars and minimize PAH.
• Supplied as water-soluble liquids, oil-soluble fractions, or spray-dried powders (on carriers such as salt or maltodextrin). Sensory span: from light “toast” to robust smoky/bacon-like notes with phenolic, carbonyl, and acidic facets.
• Use of smoke flavorings has expanded alongside barbecue popularity; in the EU they are regulated under Regulation (EU) No 1321/2013 (Union list of authorized primary smoke products and conditions of use).

Caloric value (per 100 g)
• Liquid concentrates: typically ≤20–60 kcal/100 g (energy contribution negligible at use levels).
• Powders (spray-dried): 150–380 kcal/100 g depending on carrier; still minimal at flavor dosages.

Key constituents
• Phenols (e.g., guaiacol, syringol) → core smoke character, antioxidant activity.
• Carbonyls (furfural, maltol, cyclotene) → sweet/caramelized and roasted notes.
• Organic acids (acetic, formic) → typical pH ~2.2–3.5; slight antimicrobial contribution.
• Trace lactones and other volatiles; PAH minimized by phase separation and purification.
• Analytical markers: total phenols, DNPH-carbonyls, pH, color (A₄₂₀/A₄₅₀), volatile profile by GC–MS.

Production process
• Hickory chips undergo low-oxygen pyrolysis → smoke is captured and condensed in water.
• Phase separation (aqueous vs tar), filtration/centrifugation, optional extraction/rectification to tailor top/bottom notes.
• Vacuum concentration, standardization, and spray-drying/encapsulation for powders.
• Manufactured under GMP/HACCP with controls for PAH, tars, and heavy metals.

Sensory and technological properties
• Delivers authentic smoky flavor without traditional smoking; can add light surface color and mild antioxidant effect.
• Water-soluble fractions suit brines/injections; oil-soluble fractions suit fat phases and coatings.
• Heat amplifies smoky, meaty, and toasted notes (synergy with Maillard reactions).

Food uses
• Meats and fish (brines, marinades, injections, surface sprays), BBQ sauces/glazes, snacks, cheeses/plant-based analogs, nuts, soups.
• Typical inclusion: 0.05–1.0% in finished products (optimize via pilot trials); surface treatments often 2–10% solutions.

Nutrition and health
• Used at low dosages; fat/sugar/sodium depend on the chosen system (e.g., powder carrier).
• Properly purified concentrates usually exhibit much lower PAH than many traditionally smoked foods; always comply with specifications and authorized use levels.

Safety and regulation (evidence-based notes)
• In the EU, smoke flavorings are governed by Regulation (EU) No 1321/2013, which sets the Union list of authorized primary smoke products and conditions/purity requirements.
• An in vitro hazard assessment of ten widely used liquid smoke flavorings reported:
– Genotoxicity in nearly all non-extracted samples and in all hexane-extracted samples; no genotoxicity in ethyl acetate-extracted samples.
– Oxidative stress activation in almost all extracted and non-extracted samples.
– About half the samples showed AHR and ER activities.
– Findings suggest non-polar chemicals tend to drive genotoxicity, while polar substances increase oxidative stress/cytotoxicity. Non-extracted matrices may contain compounds that antagonize toxic effects, which can be lost upon extraction.
• These results are hazard-based (cell models) and do not equal a full risk assessment at typical food-use levels. They inform prudent fraction selection (favor lighter cuts), supplier qualification, dose control, and verification of PAH and other markers.

Quality and specifications (typical topics)
• pH, total phenols, DNPH-carbonyls, density/°Plato, color; PAH within spec; absence of insolubles/tar.
• Microbiology within limits; powders free of pathogens.
• Solubility (water/oil), stability in salty/acidic matrices; full declaration of carriers for powders.

Storage and shelf-life
• Store cool and dark in airtight containers (HDPE or 316L stainless steel for liquids); protect from oxygen and moisture.
• Powders: keep dry, tightly sealed; consider desiccant sachets.
• Typical shelf-life 12–24 months per specification; apply FIFO.

Allergens and safety
• No inherent major allergens; verify carriers (e.g., maltodextrin source) and any added sulfites.
• Highly acidic liquids may be corrosive to unsuitable steels—use compatible materials.
• End-to-end GMP/HACCP and traceability required.

INCI functions in cosmetics
• Listed as Aroma/Flavor; niche masking/smoky note in oral-care or novelty products.

Troubleshooting
• Bitterness/astringency: overdosing or heavy phenolic cut → reduce dose, switch to lighter fractions, balance with sweetness/fat.
• Over-dark color/precipitates: tar carryover or heat abuse → improve clarification/filtration; select lighter grades.
• Phase separation in brines: solubility mismatch → use water-soluble fractions or emulsify.
• Metallic notes/corrosion: incompatible plant materials → switch to HDPE/316L and monitor pH.

Sustainability and supply chain
• Source certified hardwoods; capture/abate VOC emissions from pyrolysis.
• Wastewater managed to BOD/COD targets; heat recovery on hot gas streams; recyclable packaging.
• Supplier audits and routine checks for PAH and sensory markers.

Conclusion
Natural hickory smoke concentrate enables controlled, repeatable smokiness with reduced PAH when properly purified. In light of current in vitro evidence, favor lighter fractions, verify toxicological/quality markers, and optimize dosage and processing within the EU regulatory framework to deliver clean, authentic results.

Mini-glossary
• PAH — Polycyclic aromatic hydrocarbons: pyrolysis-derived contaminants that must be minimized and monitored.
• DNPH — 2,4-Dinitrophenylhydrazine: reagent/method to derivatize and quantify carbonyls (often via HPLC).
• GC–MS — Gas chromatography–mass spectrometry: identification/quantification of smoke volatiles (phenols, carbonyls, lactones).
• AHR — Aryl hydrocarbon receptor: xenobiotic-sensing receptor; some smoke fractions show activity.
• ER — Estrogen receptor: receptor with observed activities in a subset of samples in vitro.
• ROS — Reactive oxygen species: drivers/markers of oxidative stress in cells.
• VOC — Volatile organic compounds: gaseous emissions from pyrolysis requiring capture/abatement.
• GMP — Good Manufacturing Practice: hygiene and process-control standards throughout production.
• HACCP — Hazard Analysis and Critical Control Points: preventive food-safety system with defined CCP.
• BOD/COD — Biochemical/Chemical Oxygen Demand: indicators of wastewater organic load and environmental impact.
• FIFO — First in, first out: stock rotation that uses older lots first.
• CCP — Critical Control Point: step where a control prevents/reduces a specific hazard.

Smoked flavoring products have increased in recent decades as barbecue use has expanded and are regulated in Europe by Regulation (EC) No. 1321/2013 (1). In this study, ten commonly used liquid smoke flavorings were analyzed and used two different solvents to investigate whether polar or nonpolar substances have the ability to cause toxic effects. The results indicated that the liquid smoke flavorings contain compounds with hazardous properties (2).

References_____________________________________________________________________

(1) https://eur-lex.europa.eu/legal-content/IT/TXT/PDF/?uri=CELEX:32013R1321

(2) Selin E, Mandava G, Vilcu AL, Oskarsson A, Lundqvist J. An in vitro-based hazard assessment of liquid smoke food flavourings. Arch Toxicol. 2022 Feb;96(2):601-611. doi: 10.1007/s00204-021-03190-1. Epub 2021 Nov 20. PMID: 34799742; PMCID: PMC8837572.

Abstract. Liquid smoke products are widely used as a food additive to create a desired smoke flavour. These products may contain hazardous chemicals generated during the wood-burning process. However, the toxic effects of these types of hazardous chemicals constituting in the commercially available products are largely unknown. Therefore, a test battery of cell-based in vitro methods, covering different modes of actions of high relevance to human health, was applied to study liquid smoke products. Ten liquid smoke flavourings were tested as non-extracted and extracted. To assess the potential drivers of toxicity, we used two different solvents. The battery of in vitro methods covered estrogenicity, androgenicity, oxidative stress, aryl hydrocarbon receptor activity and genotoxicity. The non-extracted samples were tested at concentrations 0.002 to 1 μL liquid smoke flavouring/mL culture medium, while extracted samples were tested from 0.003 to 200 μL/mL. Genotoxicity was observed for nearly all non-extracted and all hexane-extracted samples, in which the former had higher potency. No genotoxicity was observed for ethyl acetate-extracted samples. Oxidative stress was activated by almost all extracted and non-extracted samples, while approximately half of the samples had aryl hydrocarbon receptor and estrogen receptor activities. This study used effect-based methods to evaluate the complex mixtures of liquid smoke flavourings. The increased bioactivities seen upon extractions indicate that non-polar chemicals are driving the genotoxicity, while polar substances are increasing oxidative stress and cytotoxic responses. The differences in responses indicate that non-extracted products contain chemicals that are able to antagonize toxic effects, and upon extraction, the protective substances are lost.  © 2021. The Author(s).

_
Rambla-Alegre M, Tienpont B, Mitsui K, Masugi E, Yoshimura Y, Nagata H, David F, Sandra P. Coupling gas chromatography and electronic nose detection for detailed cigarette smoke aroma characterization. J Chromatogr A. 2014 Oct 24;1365:191-203. doi: 10.1016/j.chroma.2014.09.015.

Wang H, Chambers E 4th, Kan J. Sensory Characteristics of Combinations of Phenolic Compounds Potentially Associated with Smoked Aroma in Foods. Molecules. 2018 Jul 26;23(8). pii: E1867. doi: 10.3390/molecules23081867.

Abstract. The sensory characteristics of phenolic compounds combinations were evaluated. A highly trained descriptive panel evaluated combinations of chemicals (two chemicals at a time) containing either one smoky aroma and one non-smoky aroma chemical compound, two smoky aroma chemicals, or two non-smoky aroma chemicals. The non-smoky compounds had been associated with smoke aroma in other studies, but were not found to be smoky when tested individually. Smoked flavor characteristics and intensities were changed significantly when two phenolic compounds were combined. Non-smoky phenolic compounds often contributed the smoked flavor when combined with one smoky phenolic compound or another non-smoky phenolic compound. It is necessary to understand the sensory characteristics of compound combinations as well as individual compounds.

Parker JK, Lignou S, Shankland K, Kurwie P, Griffiths HD, Baines DA. Development of a Zeolite Filter for Removing Polycyclic Aromatic Hydrocarbons (PAHs) from Smoke and Smoked Ingredients while Retaining the Smoky Flavor. J Agric Food Chem. 2018 Mar 14;66(10):2449-2458. doi: 10.1021/acs.jafc.6b05399.

Abstract. The popularity of smoked foodstuffs such as sauces, marinades, and rubs is on the rise. However, during the traditional smoking process, in addition to the desirable smoky aroma compounds, harmful polycyclic aromatic hydrocarbons (PAHs) are also generated. In this work, a selective filter was developed that reduces PAH concentrations in a smoke by up to 90% while maintaining a desirable smoky flavor. Preliminary studies using a cocktail of 12 PAHs stirred with a zeolite showed the potential for this zeolite to selectively remove PAHs from a simple solution. However, pretreatment of the smoke prior to application removed the PAHs more efficiently and is more widely applicable to a range of food ingredients. Although volatile analysis showed that there was a concomitant reduction in the concentration of the smoky compounds such as 2-methoxyphenol (guaiacol), 2-methylphenol ( o-cresol), and the isoeugenols, sensory profiling showed that the difference in perception of flavor was minimal.