Abstract This study aimed to experimentally investigate the effect of sugar syrup additions on quality measurements of honey and to detect adulteration. For that purpose, two different pure blossom ...honey samples were adulterated by directly mixing 0%, 5%, 10%, 20%, 30%, 40%, and 50% of commercially available glucose–fructose corn syrup and maltose corn syrup. In this regard, key physico-chemical properties like moisture, pH, free acidity, proline, diastase number, color (L, a, b and Delta-E), electrical conductivity, HMF, sugar profile (glucose, fructose, sucrose and maltose), and C4 sugar analysis were tested. The results of the individual analysis of moisture, pH, free acidity, proline, diastase number, color, electrical conductivity, and HMF failed to detect sugar syrup adulteration. However, when principal component analysis (PCA) was utilized to analyze the data gathered from these tests, adulterations at all-syrup ratios (5–50%) were successfully detected. Graphical Abstract
In recent years, honey-producing sector has faced the increasing presence of adulterated honeys, implying great economic losses and questioning the quality of this highly appreciated product by the ...society. Due to the high sugar content of honey, sugar syrups are among its most common adulterants, being also the most difficult to detect even with isotope ratio techniques depending on the origin of the sugar syrup plant source. In this work, a honey authentication method based on HPLC-UV fingerprinting was developed, exhibiting a 100% classification rate of honey samples against a great variety of sugar syrups (agave, corn, fiber, maple, rice, sugar cane and glucose) by partial least squares-discriminant analysis (PLS-DA). In addition, the detection and level quantitation of adulteration using syrups as adulterants (down to 15%) was accomplished by partial least squares (PLS) regression with low prediction errors by both internal and external validation (values below 12.8% and 19.7%, respectively).
•Chromatographic techniques are essential for the detection of polysaccharide impurities from HFCS.•Metabolomics-based approaches allowed the detection of specific impurities from sugar syrups.•Honey ...botanical origin traceability can be assured by fingerprinting bioactive compounds.•Elemental composition appears to be the most promising approach for honey geographical origin.•Spectroscopic and screening techniques improved the capability for honey authentication.
Assessing the authenticity of honey is a serious problem that has gained much interest internationally because honey has frequently been subject to various fraudulent practices, including mislabelling of botanical and geographical origin and mixing with sugar syrups or honey of lower quality.
To protect the health of consumers and avoid competition, which could create an unstable market, consumers, beekeepers and regulatory bodies are interested in having reliable analytical methodologies to detect non-compliant honey.
This paper gives an overview of the different approaches used to assess the authenticity of honey, specifically by the application of advanced instrumental techniques, including spectrometric, spectroscopic and chromatographic methods coupled with chemometric interpretation of the data. Recent development in honey analysis and application of the honey authentication process in the Romanian context are highlighted, and future trends in the process of detecting and eliminating fraudulent practices in honey production are discussed.
Ensuring the authenticity of honey remains a top issue for scientists, since no reliable method has been developed so far to simultaneously detect all types of honey adulteration. Consequently, the ...development of simple, fast, accurate and accessible analytical tools that may provide complementary data for assessing the honey authenticity, is encouraged.
In this work a complete investigation in terms of general physicochemical properties (water content, °Brix, electrical conductivity, free acidity, pH and 5-hydroxymethylfurfural (HMF) content), major sugar composition (fructose, glucose, sucrose and maltose) and δ13C signature of honeys from beekeepers and commercial honeys of different botanical origin (acacia, polyfloral, honeydew, sunflower, rape and linden) and various industrial syrup adulterants was performed. The aim was to generate reliable information in the process of honey evaluation linked with compliance or not with the quality standards, detecting additions of C4 plants sugar syrups (e.g. cane and corn) and confirming the botanical origin.
Multivariate statistical methods, such as hierarchical cluster analysis (HCA) and principal component analysis (PCA) were applied as exploratory methods in order to examine the possible grouping of samples according to their quality. Correlations between the analyzed parameters were also performed.
Stable carbon isotope ratio analysis (SCIRA) based on achieving the differences between the δ13C values in honey and its extracted protein fraction, allows to estimate the degree of adulteration of honeys with sugar syrups produced from C4 plant sources (corn and cane), while the general physicochemical parameters, major sugar composition and HMF content represents important tracers for honey quality control appreciation. Present results showed that parameters like δ13C values of protein extracted from honey, glucose content, ratio between fructose and glucose, and electrical conductivity were significantly different, depending on the botanical origin of honeys.
•This study used δ13C signature to detect sugars syrups from corn or cane in honey.•9.7% of 62 honey samples were detected as adulterated with C4 sugars syrups.•General physicochemical parameters do not ensure the detection of adulterated honeys.•The compliance with quality standards of the investigated honeys, have been checked.•Physicochemical parameters represent tools for honey quality control assessment.
Managing pineapple waste amid increasing demand is crucial and repurposing this waste offers a sustainable solution. Pineapple stems, an overlooked resource rich in starch and lignocellulosic ...materials, were explored in this study. Enzymatic hydrolysis was used to convert the stems into sugar syrup. Optimal conditions resulted in a sugar concentration of 107.88 ± 1.56 g/L from 10% starch, using 1% (v/v) Dextrozyme and Celluclast 1.5 L. Hydrolysis was most efficient at 70 °C for starch and 40 °C for lignocellulose. The produced syrups match high fructose corn syrup (HFCS) in water activity, moisture content, and color, making them a promising alternative in food industry.
•Pineapple plant stem shown great potential as a source for sugar syrup.•Utilizing commercial enzymes, we can extract a high concentration of sugar from the starch present in the pineapple plant stem.•In comparison to lignocellulosic materials, the hydrolysis of pineapple plant stem starch yields a significantly higher amount of sugar.
Honey adulteration with sugar syrups is a widespread problem. Several types of syrups have been used in honey adulteration, and there is no available method that can simultaneously detect all of ...these adulterants. In this study, we generated a small-scale database containing the specific chromatographic and mass spectrometry information on sugar syrup markers and developed a simple, rapid, and effective ultrahigh-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) method for the detection of adulterated honey. Corn syrup, high-fructose corn syrup, inverted syrup, and rice syrup were used as honey adulterants; polysaccharides, difructose anhydrides, and 2-acetylfuran-3-glucopyranoside were used as detection markers. The presence of 10% sugar syrup in honey could be easily detected in <30 min using the developed method. The results revealed that UHPLC/Q-TOF-MS was simple and rapid.
•Triticum spelta straw was used for the production of glucose syrups.•Statistical experimental design was successfully used for hydrothermal pretreatment parameters.•Enzymatic hydrolysis of the solid ...stream yielded a 56.33 g L−1 glucose syrup.•The pretreatment liquid stream presented 16 g L−1 of hemicellulose derived sugars.•The pretreatment liquid stream presented low concentration of inhibitors.
The global climate changes related to the use fossil fuels and the oil price volatility have been feeding the interest for renewable feedstock such as the by-products of the agroindustry. This is a challenging scenario as the diversity of plant materials worldwide calls for customized pretreatment processes to achieve a significant cellulose enzymatic saccharification coupled to the preservation of the biomass cellulose content as well as to a low degradation of biomass sugars into inhibitory compounds that is a recurrent problem in biomass processing. This work reports a statistical experimental design for hydrothermal pretreatment of spelt straw (Triticum spelta) aiming to maximize the straw enzymatic conversion in glucose syrups while minimizing the formation of undesirable biomass derived inhibitors. In the best pretreatment conditions of 180 °C for 10 min it was observed a cellulose conversion yield of 52.16% that resulted in a glucose syrup with 56.33 g L−1 in a reaction mixture presenting 200 g L-1 of pretreated straw. The liquid current from the pretreatment, rich in hemicellulose derived sugars, presented 1.63 g L−1 acetic acid, 0.67 g L−1 furfural and 0.06 g L−1 HMF. The cellulose content of the pretreated straw and the corresponding glucose concentration in the hydrolysate were mathematically modeled with relative deviation smaller than 5 % as a function of pretreatment parameters temperature and pretreatment time.
High-Performance Thin-Layer Chromatography (HPTLC) was used in a chemometric investigation of the derived sugar and organic extract profiles of two different honeys (Manuka and Jarrah) with ...adulterants. Each honey was adulterated with one of six different sugar syrups (rice, corn, golden, treacle, glucose and maple syrups) in five different concentrations (10%, 20%, 30%, 40%, and 50% w/w). The chemometric analysis was based on the combined sugar and organic extract profiles’ datasets. To obtain the respective sugar profiles, the amount of fructose, glucose, maltose, and sucrose present in the honey was quantified and for the organic extract profile, the honey’s dichloromethane extract was investigated at 254 and 366 nm, as well as at T (Transmittance) white light and at 366 nm after derivatisation. The presence of sugar syrups, even at a concentration of only 10%, significantly influenced the honeys’ sugar and organic extract profiles and multivariate data analysis of these profiles, in particular cluster analysis (CA), principal component analysis (PCA), principal component regression (PCR), partial least-squares regression (PLSR) and Machine Learning using an artificial neural network (ANN), were able to detect post-harvest syrup adulterations and to discriminate between neat and adulterated honey samples. Cluster analysis and principal component analysis, for instance, could easily differentiate between neat and adulterated honeys through the use of CA or PCA plots. In particular the presence of excess amounts of maltose and sucrose allowed for the detection of sugar adulterants and adulterated honeys by HPTLC-multivariate data analysis. Partial least-squares regression and artificial neural networking were employed, with augmented datasets, to develop optimal calibration for the adulterated honeys and to predict those accurately, which suggests a good predictive capacity of the developed model.
The industrial production of sugar syrups from lignocellulosic materials requires the conduction of the enzymatic hydrolysis step at high-solids loadings (i.e., with over 15% solids w/w in the ...reaction mixture). Such conditions result in sugar syrups with increased concentrations and in improvements in both capital and operational costs, making the process more economically feasible. However, this approach still poses several technical hindrances that impact the process efficiency, known as the "high-solids effect" (i.e., the decrease in glucan conversion yields as solids load increases). The purpose of this review was to present the findings on the main limitations and advances in high-solids enzymatic hydrolysis in an updated and comprehensive manner. The causes for the rheological limitations at the onset of the high-solids operation as well as those influencing the "high-solids effect" will be discussed. The subject of water constraint, which results in a highly viscous system and impairs mixing, and by extension, mass and heat transfer, will be analyzed under the perspective of the limitations imposed to the action of the cellulolytic enzymes. The "high-solids effect" will be further discussed vis-à-vis enzymes end-product inhibition and the inhibitory effect of compounds formed during the biomass pretreatment as well as the enzymes' unproductive adsorption to lignin. This review also presents the scientific and technological advances being introduced to lessen high-solids hydrolysis hindrances, such as the development of more efficient enzyme formulations, biomass and enzyme feeding strategies, reactor and impeller designs as well as process strategies to alleviate the end-product inhibition. We surveyed the academic literature in the form of scientific papers as well as patents to showcase the efforts on technological development and industrial implementation of the use of lignocellulosic materials as renewable feedstocks. Using a critical approach, we expect that this review will aid in the identification of areas with higher demand for scientific and technological efforts.
High-gravity brewing, which can decrease production costs by increasing brewery yields, has become an attractive alternative to traditional brewing methods. However, as higher sugar concentration is ...required, the yeast is exposed to various stresses during fermentation. We evaluated the influence of high-gravity brewing on the fermentation performance of the brewer's yeast under model brewing conditions. The lager brewer's strain Weihenstephan 34/70 strain was characterized at three different gravities by adding either glucose or maltose syrups to the basic wort. We observed that increased gravity resulted in a lower specific growth rate, a longer lag phase before initiation of ethanol production, incomplete sugar utilization, and an increase in the concentrations of ethyl acetate and isoamyl acetate in the final beer. Increasing the gravity by adding maltose syrup as opposed to glucose syrup resulted in more balanced fermentation performance in terms of higher cell numbers, respectively, higher wort fermentability and a more favorable flavor profile of the final beer. Our study underlines the effects of the various stress factors on brewer's yeast metabolism and the influence of the type of sugar syrups on the fermentation performance and the flavor profile of the final beer.
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