Consumer demand for healthier alternative sweeteners and attempts to replace the most common sweetener used in chocolate, namely sucrose, continue to increase in recent times. One sucrose alternative that has not been fully explored in chocolate is palm sap-based sugar. This work investigated the impact of sucrose replacement by coconut sugar (CCS1 and CCS2) and palm sugar (CPS1, CPS2 and CPS3) on the quality attributes of dark chocolate, more particularly colour, hardness, flow behaviour and aroma profile. The results showed that chocolates formulated with palm sap-based sugar were lighter in colour and harder than the reference chocolate made with sucrose, which could be attributed to a lower particle density and a higher moisture of palm sap-based sugar than that of sucrose. Analysis of the major volatile compounds recorded the presence of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP) and high concentration of pyrazine-based compounds in the palm sap-based sugar-sweetened chocolates. The former compound (DDMP) was, however, absent in the sucrose-sweetened dark chocolate. The physicochemical properties of the sugars also had a significant effect on the rheological behaviour of the final chocolates with chocolates formulated with coconut sugar recording the highest Casson viscosity. With regard to fat melting, chocolates sweetened with palm sap-based sugar and sucrose exhibited similar melting range temperature. Palm sap-based sugar nevertheless seems to have great potential for dark chocolate applications with additional health benefits.

Quality attributes of dark chocolates formulated with palm sap-based sugar as nutritious and natural alternative sweetener

Several analytical instruments (like pyrolyzers, thermobalances, differential thermal analyzers, or calorimeters, and sometimes simply temperature-controlled reactors) can be on-line coupled to infrared spectrometers to perform evolved gas analysis (EGA). Advances in EGA techniques are currently proposed by the scientific literature because the possibility to on-line detect the nature of the released gases or vapors has become fundamental to proving a supposed reaction, either under isothermal or under heating conditions. In this review, recent analytical applications of evolved gas analysis performed by infrared spectroscopy (EGA-IR), selected among those published in the years 2013 to 2015, are collected.

FTIR-evolved gas analysis in recent thermoanalytical investigations

Optimization of NPK fertilization combined with phytoremediation of cadmium contaminated soil by orthogonal experiment.

Flue-cured tobacco (Nicotiana tabacum L.) is a major cash crop in Yunnan, China, and the yield, chemical components, and their proportions decide the quality of tobacco leaves. To understand the effects of environmental factors (soil and climatic factors) on the yield and quality of flue-cured tobacco and determine the main regulating factors, we selected three flue-cured tobacco cultivars [K326, Yunyan87 (Yun87), and Honghuadajinyuan (Hongda)] grown in the Honghe Tobacco Zone. Indices related to yield and economic traits, chemical component properties, soil physical and chemical properties, and climatic factors at different planting sites, were evaluated. We used variance analysis, correlation analysis, and redundancy analysis (RDA) in this study. The results showed that the yield and chemical component properties of flue-cured tobacco, except for the number of left leaves and plant total sugar (PTS) content, were significantly correlated with climatic factors. Particularly, the yield increased in drier and sunnier weather. In terms of the carbon supply capacity, PTS, petroleum ether (PPE), and starch contents (PS) were higher under high-altitude and high-latitude climatic conditions, whereas for the nitrogen supply capacity, plant nitrogen (PTN) and nicotine (PN) contents improved under low-altitude and low-latitude climatic conditions. PTS, reducing sugar (PRS), potassium (PTK), chlorine (PCL), and PPE contents were negatively related to soil clay content, soil pH, and soil organic matter, whereas PRS and PTK contents were positively correlated with alkali-hydrolyzed nitrogen (AN). According to RDA, the soil clay, AN, available phosphorus (AP), and soil chlorine content (SCL) strongly affected the quality of flue-cured tobacco. The quality of the K326 and Yun87 cultivars was mostly influenced by moisture, whereas the quality of the Hongda cultivar was mostly affected by temperature. In conclusion, compared with soil properties, climatic factors more significantly affect the yield and quality of Honghe flue-cured tobacco leaves.

/pdf/climatic-factors-determine-the-yield-and-quality-of-honghe-1gamk7imot.pdf

Climatic factors determine the yield and quality of Honghe flue-cured tobacco.

Exploring crystalline structural variations of cellulose during pulp beating of tobacco stems

Differentiation of tobacco leaves in different plant stalk positions in China was achieved based on basic chemical compounds and neutral volatiles by principal component analysis (PCA). The continuous flow analysis method was used to determine the quantity of the basic chemical compounds (sugars, total nitrogen and nicotine) of 30 samples. The neutral volatiles of tobaccos were analyzed by GC–MS. It was found that the disparity in basic chemical components was not enough to assess the different quality of tobacco leaves. PCA was used to reveal the differences among these three species based on neutral volatile compounds. Tobacco leaves in different positions were differentiated according to the results of PCA. Four principal components were extracted and altogether accounted for exceeding 80 % of the total variances. The first principal component explained 48.1 % of the total variation and was mainly defined by solanone, megastigmatrienone, 5-methylfurfural, furfuralcohol, phenylethylalcohol and benzylalcohol. The second principal component explained 18.1 % of the total variation and was mainly defined by β-ionone and farnesylacetone. The plots of sample loadings showed that a good differentiation on the basis of concentrations of neutral volatiles was achieved. These results demonstrated that neutral volatiles can be used as the useful variables to characterize the tobacco leaves in different positions.

Differentiation of flue-cured tobacco leaves in different positions based on neutral volatiles with principal component analysis (PCA)

The influences of various factors on the formation of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP) were investigated in a solid-state Maillard reaction system. Thermogravimetric analysis (TG) and differential scanning calorimetry analysis (DSC) showed that the solid-state Maillard reaction mainly occurred at around 150 °C. The DDMP formation from reducing sugars (glucose or fructose) and several selected amino acids (l-proline, l-alanine, l-asparagine, l-threonine, l-tyrosine and l-lysine) was compared. Proline was found to have special activity in DDMP formation when reacted with glucose because of its special catalytic action. The influences of reactant ratios, oxygen, reaction temperature and reaction time on DDMP formation from the reaction of proline with glucose were studied. Reactant molar ratios of glucose to proline played important impact on DDMP formation, and the formation of DDMP was improved when the ratio was higher than 1:1 and achieved the highest level at 2:1. Oxygen had no obvious effects on DDMP formation. The effects of reaction time and temperature were investigated together and revealed the information on the highest yield and minimum temperature for DDMP formation. Furthermore, the kinetics of DDMP formation was studied, and DDMP formation in the initial stage was shown to follow an apparent first-order reaction with an activation energy of 68.8 kJ/mol.

Influence of various factors on formation of 2,3-dihydro-3,5-dihydroxy-6-methyl-4( H )-pyran-4-one (DDMP) in a solid-state model system of Maillard reaction

The influence of potassium lactate (PL) on the combustion behavior and semi-volatile compounds of tobacco during smoking is investigated in this study. The addition of PL showed no effect on the content of total particulate matter, nicotine-free dry particulate matter, puff number, and nicotine. Meanwhile, a 22.5 % increase in moisture content and 3 % decrease in CO content of mainstream smoke were observed when the added amount of PL was up to 2 %. The differential thermogravimetric curves indicated that PL decreased the maximum combustion rate and influenced the thermal degradation stage of tobacco by shifting the peak point of temperature to a higher value. The gas evolution profiles obtained from Fourier transform infrared spectroscopy during combustion showed that PL could lower the CO and CO2 yield, but did not affect the generation of CH4 and carbonyl compounds. A great variation in semi-volatile components of the mainstream smoke was also observed from the tobacco containing PL compared with the control. The comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry analysis showed that PL increased the yield of alcohols, lactons, miscellaneous oxygenated compounds and amides, but decreased that of aldehydes, acids, pyrroles and pyrazines. A small added amount (0.2 %) of PL reduced the content of total semi-volatile substances, ketones, esters, phenols, hydrocarbons, pyridines, tobacco alkaloids, and nitrogenous compound. However, the contents of these substances were not affected when the added amount was >0.2 %. PL bound the ash during combustion, thereby leading to the change of combustion behavior and certain smoke components.

Study on the effect of potassium lactate additive on the combustion behavior and mainstream smoke of cigarettes

The influence of exogenous fiber on the generation of carbonyl compounds in reconstituted tobacco sheet

In recent years, reconstituted tobacco sheet (RTs) has played an increasingly significant role in tobacco industry. The yields of CO and carbonyl compounds (formaldehyde, acetaldehyde, acetone, acrolein, propanal, butenal, 2-butanone, and butyraldehyde) in cigarette mainstream smoke of RTs and their formation mechanisms were investigated in this paper. Self-made RTs (SRTs) was studied and compared with foreign Mauduit RTs (MRTs) and three commercial tobacco leaves on routine chemical constituents, thermal behavior, and subsequent gaseous products evolution. The cigarette smoking results illustrated that the yields of CO (2.9 mg per puff) and carbonyl compounds (about 208 μg per puff) in mainstream smoke of SRTs and MRTs were at the same level, and obviously higher than those of three commercial tobacco leaves. The routine chemical constituent results demonstrated that bright tobacco and oriental tobacco contained particularly higher contents of reducing sugar and total sugar than RTs, while burley tobacco had a high content of nitrogen compounds. The thermal behavior results showed that SRTs (11.6 % min−1) and MRTs (14.5 % min−1) presented higher maximum mass-loss rate than bright tobacco (7.8 % min−1), burley tobacco (7.1 % min−1), and oriental tobacco (6.8 % min−1). The thermal decomposition of saccharides and combustion of residual char played the most important roles in mass-loss and gaseous products formation. The decomposition of saccharides and incomplete combustion of carbonized residual char primarily contributed to the formation of CO, while carbonyl compounds evolution was mainly attributed to the decomposition of saccharides alone.

Zhilei Zhou

Papers

Differentiation of flue-cured tobacco leaves in different positions based on neutral volatiles with principal component analysis (PCA)

Influence of various factors on formation of 2,3-dihydro-3,5-dihydroxy-6-methyl-4( H )-pyran-4-one (DDMP) in a solid-state model system of Maillard reaction

Study on the effect of potassium lactate additive on the combustion behavior and mainstream smoke of cigarettes

The influence of exogenous fiber on the generation of carbonyl compounds in reconstituted tobacco sheet

The generation of carbon monoxide and carbonyl compounds in reconstituted tobacco sheet