Quantification of Allyl Methyl Sulfide, Allyl Methyl Sulfoxide, and Allyl Methyl Sulfone in Human Milk and Urine After Ingestion of Cooked and Roasted Garlic.

Wen Qin,Patrick Bauer,Andrea Buettner,Laura Scheffler,Katrin Huber,Constanze Sharapa,Moritz Popp,Helene M Loos

doi:10.3389/fnut.2020.565496

Abstract

Due to its characteristic flavor and positive effects on human health, garlic is a highly valued food ingredient. Consumption of garlic alters the quality of body odors, which may in some instances hinder social interaction but be beneficial in other contexts, as it is assumed to contribute to early flavor learning in the breastfeeding context, for example. In previous work, allyl methyl sulfide (AMS) has been identified as the major odor-active metabolite in urine and milk, being excreted together with the odorless metabolites allyl methyl sulfoxide (AMSO) and allyl methyl sulfone (AMSO2) after ingestion of raw garlic. The present work aimed to elucidate whether commonly used culinary thermal processing steps influence the excretion profiles of garlic-derived compounds. To this aim, urine (n = 6) and milk (n = 4) samples were donated before and after ingestion of roasted and cooked garlic and investigated by gas chromatography-olfactometry/mass spectrometry, and, in the case of milk, by aroma profile analysis. The concentrations of AMS, AMSO, and AMSO2 were determined by stable isotope dilution assays. Sensory evaluations revealed that a garlic-like odor was perceivable in milk samples donated after ingestion of roasted and cooked garlic. Besides AMS, AMSO, and AMSO2, no other odor-active or odorless compounds related to the ingestion of roasted or cooked garlic were detected in the urine and milk samples. Maximum concentrations of the metabolites were detected around 1–2 h after garlic intake. In some cases, a second maximum occurred around 6 h after ingestion of garlic. The cooking procedure led to a more important reduction of metabolite concentrations than the roasting procedure. These findings suggest that intake of processed garlic leads to a transfer of odor-active and odorless metabolites into milk, which contributes to early flavor learning during breastfeeding and may also have a physiological effect on the infant.

Highlights

Garlic (Allium sativum) is a common food ingredient, which is thought to originate from Central Asia where it has been cultivated for thousands of years
Gas Chromatographic-Olfactometric Screening of Urine and Milk Samples Urine samples Comparative GC-O analyses revealed the presence of one garliclike smelling compound at retention indices (RIs) 715 (DB-5) in distillates obtained from urine samples donated after consumption of roasted garlic, which was identified as allyl methyl sulfide (AMS)
In distillates obtained from urine samples donated in the cooked garlic study, no odor-active compounds related to garlic consumption were detected by GC-O

Summary

Introduction

Garlic (Allium sativum) is a common food ingredient, which is thought to originate from Central Asia where it has been cultivated for thousands of years. More recent research revealed sulfur-containing compounds as an important class of bioactive substances of garlic, having antimicrobial, anti-inflammatory, antioxidant, immunomodulatory, antihypertensive, antihyperlipidemic, cancer-preventive, and other physiological effects [2,3,4,5]. Due to these promising health benefits, a range of garlic supplements were developed by industry, generally on the basis of garlic powder or extract. The physiological effects of these different supplements were often investigated but seldom compared to the effects of garlic as it would be consumed in common dietary intake conditions [6]

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Conclusion