Energy and emission properties of burley tobacco stalk briquettes and its combinations with other biomass as promising replacement for coal

As a tobacco producer, Serbia has to deal with large amounts of leftover tobacco stalks after harvesting. One option for this type of biomass is to burn it, but burning is not encouraged in Serbia, since the levels of its combustion products have not been investigated yet. The aim of this study was therefore to determine the elemental composition, ash and nicotine content, heat values, and composition of gaseous combustion products of tobacco stalk briquettes and to see if their mixing with other types of biomass available in Serbia could improve their ecological profile. We made 11 different types of briquettes: six of pure raw materials, including burley tobacco stalks, sunflower head remains, wheat straw, corncob, soy straw, and beech sawdust and five by mixing tobacco stalks with these other raw materials in a 50:50 mass ratio. All briquettes meet the ecological criteria regarding the emission limits for nitrogen oxides (NO_x), sulphur dioxide, carbon monoxide, and carbon dioxide. Nicotine content in flue gases (<10 mg/kg) is far below the maximum level allowed by the European Union. Heat values of all biomass samples are acceptable, although lower than those specified for solid biofuels (≥16.0 MJ/kg), save for corncob and beech sawdust and their mixtures with tobacco stalks. Our findings therefore encourage the use of tobacco stalks as a viable biofuel.

Development of a MAGIC population and high-resolution quantitative trait mapping for nicotine content in tobacco

Multiparent Advanced Generation Inter-Cross (MAGIC) population is an ideal genetic and breeding material for quantitative trait locus (QTL) mapping and molecular breeding. In this study, a MAGIC population derived from eight tobacco parents was developed. Eight parents and 560 homozygous lines were genotyped by a 430K single-nucleotide polymorphism (SNP) chip assay and phenotyped for nicotine content under different conditions. Four QTLs associated with nicotine content were detected by genome-wide association mapping (GWAS), and one major QTL, named qNIC7-1, was mapped repeatedly under different conditions. Furthermore, by combining forward mapping, bioinformatics analysis and gene editing, we identified an ethylene response factor (ERF) transcription factor as a candidate gene underlying the major QTL qNIC7-1 for nicotine content in tobacco. A presence/absence variation (PAV) at qNIC7-1 confers changes in nicotine content. Overall, the large size of this MAGIC population, diverse genetic composition, balanced parental contributions and high levels of recombination all contribute to its value as a genetic and breeding resource. The application of the tobacco MAGIC population for QTL mapping and detecting rare allelic variation was demonstrated using nicotine content as a proof of principle.

Nicotine content in Swedish type snus sold in Norway from 2005 to 2020

Introduction

Use of snus (moist smokeless tobacco) is widespread in Scandinavia and increasingly popular in the U.S. Snus products vary in terms of product design, portion size, and nicotine content. The aim of this study was to examine variations in the nicotine content in snus sold on the Norwegian market from 2005 to 2020.

Methods

We calculated the nicotine content in dry snus in milligram per gram (mg/g) and milligram per serving (mg/s), weighted by the products’ market share from data on nicotine content, water content, and portion size (both for portion and loose snus) for the ten most sold snus products from each of the three largest manufacturers in 2005, 2010, 2015, and 2020.

Results

In all snus products combined, the nicotine content per gram snus (mg/g) increased from 16.3 to 24.1, while nicotine per serving (mg/s) was stable around 13.0. In portion snus, the nicotine content increased for both mg/g and mg/s, most notably from 2005 to 2010. In loose snus, mg/g decreased marginally, while mg/s was stable throughout the period.

Conclusions

In a period with increasing snus use, the nicotine content in snus increased per gram snus, but not per serving. The stability in nicotine per serving is likely due to a decreasing market share of loose snus which accounted for 54% of the snus products in 2005 and 5% in 2020, and which traditionally has a high content of nicotine per serving.

Implications

Use of snus is popular in Scandinavia, most notably in Sweden and Norway, but also increasingly common in Finland, especially among young adults. There are no prior market-based studies of variations in the nicotine content in Swedish snus over time. We found that the average amount of nicotine per gram snus sold on the Norwegian market increased in the period 2005 to 2020, most notably from 2005 to 2010, while the amount of nicotine per serving was stable in the same period, primarily due to a decreasing share of loose snus.

Appeal, subjective effects, and relative reinforcing effects of JUUL that vary in flavor and nicotine content

The U.S. Food and Drug Administration has the authority to regulate characteristics of electronic nicotine delivery systems (ENDS). Prior research indicates that regulation of certain characteristics of these products may have an effect on their appeal and use. Policies that affect appeal and use of ENDS are relevant to attempts to reduce use among young people-including young adults-but are also relevant to adults who use these products as harm reduction tools. Using a novel concurrent choice task, we evaluated the relative reinforcement of JUUL brand ENDS products that varied in flavor (n = 8) and nicotine (n = 8) among samples of young adults who use JUUL. Findings suggest that restricting JUUL flavor to tobacco-only results in decreased appeal, while reducing the nicotine content of JUUL pods to 3%-from the conventional 5%-does not have an effect on product appeal. Findings also validate a novel methodology for delivering fixed doses of ENDS vapor within the context of a task that assesses the relative reinforcement of ENDS products with varying characteristics. This methodology can be applied to assessing the relative reinforcing effects of a wide variety of tobacco products with varied characteristics. (PsycInfo Database Record (c) 2021 APA, all rights reserved).