Geographical and botanical origin of honeys can be characterized on the basis of physico-chemical composition, sensory properties and on the basis of melissopalynological analysis. No comprehensive description of the characteristics of Czech honey has been published so far. This study provides insights that are important for correct classification. The study analysed 317 samples of authentic honey from randomly selected localities. Due to the diversity of the landscape, the typical honey of the region is blend honey with a predominance of blossom honey. According to the pollen profile and electric conductivity, the honeys were sorted into the following: Brassica honey (BH), Floral honey (FH), Fruit tree honey (PH), Honeydew (HD), Lime tree honey (LH), Robinia pseudoacacia honey (RH), and Trifolium honey (TH). Physico-chemical properties, including higher carbohydrates, were determined for the honeys and their pollen profiles were examined. The physico-chemical properties and pollen profile are partially in compliance with the description of European monofloral honeys, except for RH and TH. Although they had the highest proportion of acacia pollen, amounting to >10% of all the Czech honeys, these RH honeys differ from the European standard, so they cannot be considered acacia honey. Further, PH honeys and FH polyfloral honeys were described. Most honeys contained a significant proportion of rapeseed pollen, which is one of the common agricultural crops grown in the Czech Republic. All the analysed honeys met the parameters defined by the legislation. Due to direct on-site sampling, honeys were characterized by a low 5-(hydroxymethyl)furfural (HMF) content (3.0 mg/kg) and high diastase activity (24.4 DN). Honeydew honeys had the highest proportion of higher carbohydrates, primarily of Melezitose (4.8 g/100 g) and Trehalose (1.3 g/100 g). The presence of higher carbohydrates was also confirmed in LH for Maltose (4.6 g/100 g) and Turanose (2.4 g/100 g).

Anthocyanins are flavonoid substances of plant origin with potential antioxidant effects. Because of their intense colors, they are used as natural dyes in food. However, their stability in food matrices is limited. This study aimed to verify the effect of selected carbohydrates on the stability of anthocyanins (cyanidin-3-O-β-glucopyranoside, cyanidin-3-O-β-galactopyranoside, cyanidin-3-O-β-rutinoside and delphinidin-3-O-β-rutinoside) during the accelerated storage test, since carbohydrates help to preserve the typical color of anthocyanins, increase their shelf-life and availability in the organism, and reduce losses during processing. Moreover, the kinetic parameters of anthocyanin degradation (E_a, k, t_1/2) were determined. Sucrose was found to have the greatest potential for retarding anthocyanin degradation during storage, whereas fructose exerted an accelerating effect. Glycosidation of anthocyanin aglycone had no significant effect in terms of their stability. Anthocyanin degradation was significantly positively correlated with the change in the a* parameter (redness), and subsequently, a significant positive correlation was observed in the determination of the kinetic parameters for anthocyanins and the a* parameter. The highest stability of anthocyanins was observed in the presence of sucrose and their degradation can be predicted by the value of the a* parameter, which would also be a very fast and non-destructive method for food processing companies.

Sulphite is?a?food additive used worldwide. Globally, for concentrations above 10 mg·kg–1, sulphite compounds must be?labelled as?sulphur dioxide (SO2) on?the packaging due to?their potential health risks. This study compares ...

The quality of black/red currant products, which are valuable components of a healthy diet, depends on many aspects, e.g., natural variability, climatic conditions, degree of ripeness, processing technology, and recipe. The aim of the study was to assess the effect of the harvest year (2020 and 2021) and different processes (with or without prepress enzymatic treatment) on the chemical composition of 38 laboratory-prepared black/red currant (BC/RC) juices and to compare them with 19 selected commercial products, using 20 compositional and quality markers. Significant differences (p < 0.01) were observed for BC in sucrose, Dp-3-glu, and Cy-3-glu content within the different processes, as well as fructose and ascorbic acid content within the harvest year (p < 0.05). The greatest differences between BC and RC juices were observed in ascorbic acid content (1567 mg/kg in BC and 261 mg/kg in RC), citric acid content (34.6 g/kg in BC and 23.2 g/kg in RC), and in the anthocyanin profile. The major anthocyanins of the currant products were identified as Dp-3-rut (39.1–50.4%), Cy-3-rut (30.1–39.1%), Cy-3-glu (3.6–18.2%), and Dp-3-glu (9.4–13.5%) in BC and Cy-3-glu (59.3–67.2%) and Cy-3-rut (14.2–19.8%) in RC. The chemical composition of commercial products was found to be highly variable and dependent on the recipe used.

Lemon juice and other lemon-based beverages are subject to economically motivated fraud, primarily inclu­ding a reduced fruit content closely related to excessive dilution with water, undeclared addition of sugars or synthetic citric acid, and substitution of lemons with cheaper fruit. Eight tested samples of 100% juices showed good agreement between the measured concentrations and the reference values for the following markers: formol number (range from 16.9 to 26.5 mL of 0.1M NaOH 100 mL–1), ash (2.5 to 3.9 g L–1), phosphorus (84 to 145 mg L–1), potassium (931 to 1720 mg L–1), magnesium (81 to 114 mg L–1), malic acid (1.8 to 6.0 g L–1), and ᴅ‑isocitric acid (277 to 560 mg L–1). The following markers were suggested as an evidence of adulteration, processing method, and recipe alteration after the subsequent analysis of the beverage concentrates: 1) Citric acid is a substance whose content can be increased by adding synthetic citric acid. 2) Calcium content was impacted by clarification or reconstitution in some beverage concentrate samples tested. 3) Increased content of glucose and fructose confirmed exogenous sugar addition. 4) Ascorbic acid levels below 150 mg L–1 indicated severe processing or long-term storage. The flavonoid profile, characterized mainly by the ratio of eriocitrin and hesperidin (average value 0.7), serves as an indicator of the addition of another citrus species. However, the finding for the Interdonato variety suggests that this ratio is quite variable and not entirely specific because lime juice exhibits a similar value. Citronová šťáva a další nápoje na bázi citronů podléhají ekonomicky motivovaným podvodům, mezi které primárně patří snížený obsah ovoce úzce spojený s nadměrným naředěním vodou, nedeklarovaným přídavkem cukrů nebo syntetické citronové kyseliny a záměnou citronů levnějším druhem ovoce. U 8 testovaných vzorků 100% šťáv byla potvrzena dobrá shoda naměřených koncentrací s referenčními hodnotami u těchto znaků: formolové číslo (rozsah 16,9 až 26,5 ml 0,1M NaOH 100 ml–1), popel (2,5 až 3,9 g l–1), fosfor (84 až 145 mg l–1), draslík (931 až 1720 mg l–1), hořčík (81 až 114 mg l–1), jablečná kyselina (1,8 až 6,0 g l–1) a ᴅ-isocitronová kyselina (277 až 560 mg l–1). Po následném proměření nápojových koncentrátů byly jako indikátory falšování, způsobu zpracování a úpravy receptury doporučeny tyto markery: 1) obsah citronové kyseliny, jejíž nálezy mohou být zvýšeny přídavkem citronové kyseliny syntetického původu, 2) obsah vápníku, který byl u řady testovaných vzorků ovlivněn čiřením nebo rekonstitucí koncentrátu, 3) zvýšená hodnota glukosy a fruktosy potvrzovala exogenní přídavek cukrů, 4) pokles askorbové kyseliny pod 150 mg l–1 vypovídal o nešetrném zpracování nebo dlouhodobém skladování. Profil flavonoidů charakterizovaný především poměrem eriocitrinu a hesperidinu (průměrná hodnota 0,7) slouží jako indikátor přídavku jiného citrusového druhu. Je však třeba brát v potaz, že je poměrně variabilní, což ukázal nález zjištěný pro odrůdu Interdonato a ne zcela specifický, protože obdobný poměr vykazuje i šťáva z limet.

Benzoic acid (BA, E210) is a common food preservative and naturally occurring plant metabolite. It exists in plant tissues as free (f‐BA) and bound (b‐BA) forms. This makes accurate quantification challenging, as traditional extraction methods may underestimate total BA content. In this study, 26 berries and plum samples of 7 Vaccinium and Prunus taxa were analyzed by conventional shaking extraction (CSE, f‐BA) and ultrasound‐assisted extraction (UAE, total releasable f‐BA + b‐BA). Benzoic acid concentrations ranged from 4.1 to 581.8 mg/kg across taxa, with wild‐harvested V. macrocarpon reaching the highest levels and V. oxycoccos approximately 15‐fold lower. UAE increased measured BA over CSE in every sample (16%–41%), with a consistent gain of ∼20% in V. macrocarpon and Prunus spp. regardless of concentration, but a more variable and higher gain (up to 41%) in V. myrtillus , suggesting species‐dependent differences in BA binding within the cell wall. This shows the extraction method strongly affects measured BA content, relevant for EU food additive compliance. The results support UAE as a more reliable, though not absolute, estimate of total BA (t‐BA) in fruit products. These findings highlight the need for harmonized extraction protocols for compliance testing and further validation of UAE in other fruit and food matrices.