Determination of some quality parameters of honey bee feed

The present study was performed to determine the impact of feeding honeybee colonies with sugar syrup and inverted sugar on pollen, physiochemical and antimicrobial properties. Raw honeys and bee-processed syrups (sucrose solution or inverted sugar syrup) samples were collected from bee colonies under field conditions in different regions of Egypt. Biological activities were compared between colonies which fed with sugar syrup and inverted sugar. The results obtained clearly showed that the chemical analysis of tested samples indicated that concentration of monosaccharide (fructose and glucose) was the highest in samples from natural honey. In contrast, disaccharide (sucrose) concentration was lowest compared to the samples collected from colonies fed with inverted sugar and sugar syrup. The antibacterial activity of natural honey from the Assiut region was highest against Staphylococcus aureus compared to honey obtained from bee colonies fed on sucrose solution and inverted sugar syrup. Only honey samples of colonies which feed with inverted sugar (Qualiubia region), sugar syrup (Arish region) at 100% concentration caused antimicrobial activity against Staphylococcus aureus. However, the effect against Pseudomonas aeruginosa was observed only with honey sample (100%) harvested from colonies fed with sugar syrup at Arish region. A wide range with highest value of H₂O₂ (201.30 and 139.72 mg/kg) was observed in natural honey samples and honey obtained from colonies fed on inverted sugar from Arish region. The water contents of honey collected from colonies fed with sugar syrup in Qualiubia and Arish regions, or fed on inverted sugar in Arish reached the highest value. The results obtained also showed that the pollen grains content, H₂O₂ and antimicrobial activity were reduced in the harvested honey samples of honeybee colonies fed with inverted sugar and sugar syrup in most regions. In contrast, these diets increased the water content and improved biological activity in colonies fed with inverted sugar, compared to that fed on sugar syrup. Keywords: Honeybee inverted sugar, sugar syrup, Pseudomonas aeruginosa, Staphylococcus aureus.

Sugary solutions

The aim of this study is to compare the environmental impact of liquid inverted sugar (77°Bx) produced with enzymatic hydrolysis of beet sugar and HFCS (75% DM) produced from corn in a wet milling process. Given the different sweetness equivalents of liquid inverted sugar (77°Bx) and HFCS (75% DM), the reference flows were defined as 900 kg of liquid inverted sugar or 1000 kg HFCS. The analysis was performed with the life cycle assessment (LCA) method focusing on the cradle-to-gate stage. The inventory data of liquid inverted sugar processing were supplied by a producer while the LCA of HFCS relies on secondary data (literature) which describes the material and energy flows associated with glucose production. Life cycle inventory of relevant inputs and outputs were available from the Ecoinvent 3.4 database. Environmental impacts were calculated with the ReCiPe 2016 (H) life cycle impact assessment (LCIA) method. LCA results have revealed that inverted liquid sugar has a lower impact in 14 out of the 18 analysed impact categories. Consumption of inverted liquid sugar (>77°Bx) instead of HFCS (75% DM) could lead to significant reduction in GHG emissions (by 38%), fossil energy (by 31%) and water (by 95%) consumption, and reduces the required land area by 67%.

Introduction: Palm syrup is a typical product from the Canary Islands, traditionally produced from the sap of the tropical palm tree Phoenix canariensis. Its high caloric content has led to its increasing use as a health food supplement for athletes, children and elderly. Furthermore, demand for this natural syrup is continuously increasing due also to its medicinal uses in homeopathic medicine. Objective: Palm Tree syrup samples prepared with palm sap from primary producers in La Gomera island (Canary Islands, Spain) were analyzed for their nutritional composition (moisture, ash, sugars, fat, vitamins and minerals). Methods: 35 syrup samples from five different producing regions in La Gomera island were analyzed. High-performance liquid chromatography (HPLC) was used to determine sugars and vitamins and Flame Atomic Absorption Spectrophotometry (FAAS) was used to analyze the minerals. Results: Major carbohydrates were sucrose (37.8%), glucose (9.50%) and fructose (4.80%), respectively. The presence of arabinose could not be confirmed. Niacin was the water-soluble vitamin with the highest concentration with an average content of 0.003%. Fat content was found to be under 0.20%. Potassium was the mineral with highest contents (0.45%). Conclusions: Results suggest that palm tree syrup can play an important role as a sugar and mineral source in human nutrition, suggesting that future applications for this product could be developed.

The maximum amount of free acid in Valencia orange fruits was found to develop early in the season and to change very little from that time on. The concentration of free acids in the juice (milligrams per milliliter), however, lessens considerably during fruit development. This decrease in free acidity, with the corresponding increase in pH, was due chiefly to the decrease in concentration of free citric acid. Although the malic-acid concentration in the juice (milligrams per milliliter) stayed nearly uniform during the season, the actual amount in the fruit increased. The concentration of combined acids remained nearly uniform in the fruit, but the absolute amount per fruit increased. The amounts of combined acids determined from the alkalinity of the ash were in agreement with the values determined from the difference between the totaland free-acid radicals. During ripening, the changes in pH of the juice were definitely related to changes in percentages of the total-acid radical in the free form. A similar relation was noted between pH and the percentage of free acid expressed on a fresh-weight basis.

The objectives of this research are (1) to know the effect of acid type and concentration on the hydrolysis of Taro tuber starch into liquid sugar (2) to know the type and concentration of acid that can produce the best liquid sugar characteristic in the hydrolysis of Taro tuber starch. The study used a complete randomized design with two factorial patterns. There are the type and concentration of acid used for the hydrolysis of Taro tuber starch. The variables observed were sugar reduction and liquid sugar clarity. The results showed that the type and concentration of acids and their interactions significantly affected the Dextrose Equivalent of liquid sugar produced. The best treatment is hydrolysis using nitric acid (HNO3) with 6% concentration with Dextrosa Equivalent is 57,470 %.

SUMMARY The experiment was conducted in a private apiary on 12 Carpathian Foti bee families. The bees were kept in multi-tier beehives. The resi stance to wintering was evaluated according to several apicultural parameters: state of the families, manner of wintering, size of the population, quality of the queen. The contro l group received no feeding supplement, group 1 received supplemental feeding consisting of syrup with pollen replacer during autumn, while group 2 received supplemental feeding consisting of syrup with pollen replacer during autumn and cakes during winter. The use of the pollen replacer in autumn increased egg laying during this period increasing thus the size of the population over the winter. The supplemental cakes with pollen replacer given over winter stimulated bees resistance to wintering, bee mortality being signif icantly lower.

The high-sugar products discussed in this chapter are referred to as chocolate, sugar confectionery (non-chocolate), liquid sugars, sugar syrups, and honey. Products grouped in the sugar confectionery category include hard candy, soft/gummy candy, caramel, toffee, licorice, marzipan, creams, jellies, and nougats. A common intrinsic parameter associated with high-sugar products is their low water activity (aw), which is known to inhibit the growth of most spoilage and pathogenic bacteria. However, spoilage can occur as a result of the growth of osmophilic yeasts and xerophilic molds (Von Richter, 1912; Anand & Brown, 1968; Brown, 1976). The aw range for high-sugar products is between 0.20 and 0.80 (Banwart, 1979; Richardson, 1987; Lenovich & Konkel, 1992; ICMSF, 1998; Jay, Loessner, & Golden, 2005). Spoilage of products, such as chocolate-covered cherries, results from the presence of yeasts in the liquid sugar brine or the cherry. Generally, the spoiled product will develop leakers. The chocolate covering the cherry would not likely be a source of yeast contamination.

Starch debranching enzymes that merely hydrolyze α-(1→6) glycosidic linkages are classified into isoamylases (EC 3.2.1.68) and pullulanases (EC 3.2.1.41). An exception to this definition would be amylopullulanase, a type of pullulanase that is capable of cleaving both α-(1→4) and α-(1→6) linkages. Amylopullulanases are in demand in liquid sugar industries to generate glucose and some other starch derivatives. Pullulanases can be used in conjunction with amylases to improve sugar availability during sugar syrup production. Here, a thermophilic Cohnella sp. A01 amylopullulanase (EC 3.2.1.41) gene, namely Coh4159, was PCR amplified and cloned in pET-26b(+) and transformed into BL21(DE3). Recombinant Coh4159 was heterologously expressed in the presence of 0.5 mM IPTG and purified via affinity chromatography, and further characterized. Enzyme activity was demonstrated via zymogram analysis in the presence of pullulan. The enzyme had a hydrolytic effect on pullulan with Vmax = 2.85 µmol.min-1 and Km = 0.5 mM. Temperature optima and pH were 60 ˚C and 6.0. In which the enzyme kept its activity at wide pH (4-9) and temperature (30-70 ˚C) ranges. The recombinant enzyme kept 50% of its activity for 60 min, 100 min and 120 min when incubated at 80, 70 and 60 ˚C, respectively. Amongst metal ions tested, Mn2+, and Ca2+ have improved the enzyme activity both at 5 and 10 mM. The results promise the capability of producing a commercial industrial enzyme, well-suited to liquid sugar syrup industry specification.

Starch debranching enzymes that merely hydrolyze α-(1→6) glycosidic linkages are classified into isoamylases (EC 3.2.1.68) and pullulanases (EC 3.2.1.41). An exception to this definition would be amylopullulanase, a type of pullulanase that is capable of cleaving both α-(1→4) and α-(1→6) linkages. Amylopullulanases are in demand in liquid sugar industries to generate glucose and some other starch derivatives. Pullulanases can be used in conjunction with amylases to improve sugar availability during sugar syrup production. Here, a thermophilic Cohnella sp. A01 amylopullulanase (EC 3.2.1.41) gene, namely Coh4159, was PCR amplified and cloned in pET-26b(+) and transformed into BL21(DE3). Recombinant Coh4159 was heterologously expressed in the presence of 0.5 mM IPTG and purified via affinity chromatography, and further characterized. Enzyme activity was demonstrated via zymogram analysis in the presence of pullulan. The enzyme had a hydrolytic effect on pullulan with Vmax = 2.85 µmol.min-1 and Km = 0.5 mM. Temperature optima and pH were 60 ˚C and 6.0. In which the enzyme kept its activity at wide pH (4-9) and temperature (30-70 ˚C) ranges. The recombinant enzyme kept 50% of its activity for 60 min, 100 min and 120 min when incubated at 80, 70 and 60 ˚C, respectively. Amongst metal ions tested, Mn2+, and Ca2+ have improved the enzyme activity both at 5 and 10 mM. The results promise the capability of producing a commercial industrial enzyme, well-suited to liquid sugar syrup industry specification.

The major compounds in honey are carbohydrates such as monosaccharides and disaccharides. The same compounds are found in cane-sugar concentrates. Unfortunately when sugar concentrate is added to honey, laboratory assessments are found to be ineffective in detecting this adulteration. Unlike tracing heavy metals in honey, sugar adulterated honey is much trickier and harder to detect, and traditionally it has been very challenging to come up with a suitable method to prove the presence of adulterants in honey products. This paper proposes a combination of array sensing and multi-modality sensor fusion that can effectively discriminate the samples not only based on the compounds present in the sample but also mimic the way humans perceive flavours and aromas. Conversely, analytical instruments are based on chemical separations which may alter the properties of the volatiles or flavours of a particular honey. The present work is focused on classifying 18 samples of different honeys, sugar syrups and adulterated samples using data fusion of electronic nose (e-nose) and electronic tongue (e-tongue) measurements. Each group of samples was evaluated separately by the e-nose and e-tongue. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were able to separately discriminate monofloral honey from sugar syrup, and polyfloral honey from sugar and adulterated samples using the e-nose and e-tongue. The e-nose was observed to give better separation compared to e-tongue assessment, particularly when LDA was applied. However, when all samples were combined in one classification analysis, neither PCA nor LDA were able to discriminate between honeys of different floral origins, sugar syrup and adulterated samples. By applying a sensor fusion technique, the classification for the 18 different samples was improved. Significant improvement was observed using PCA, while LDA not only improved the discrimination but also gave better classification. An improvement in performance was also observed using a Probabilistic Neural Network classifier when the e-nose and e-tongue data were fused.

The acute and chronic toxicity to honeybees, <i>Apis mellifera</i> of water guttation and dew collected from winter rape plants treated with the insecticide Nurelle D<sup>®</sup> (a.i. chlorpyriphos + cypermethrin) was investigated. Caged bees were fed on sugar syrup containing water guttation and dew for 24 h (acute toxicity test) and for 10 days (chronic toxicity test). Bee mortality and food consumption were determined daily. A contact toxicity test was performed within 24 h on bees kept in Petri dishes (10 bees per dish) lined with filter paper saturated with the test solution. The acute Nurelle D<sup>®</sup> contact and oral toxicity tests showed that the mortality of bees treated with water guttation and dew collected from the treated plants did not exceed 10%. A chronic toxicity test showed that adding contaminated water guttation and dew to the syrup caused an insignificant increase in bee mortality and reduced the syrup consumption significantly. The chlorpyriphos residue found in contaminated water guttation and dew were below the limit of detection (0.8 µg/kg) and the cypermethrin residue was below the detection levels.

Free acid was found in the fasting gastric contents of each of 13 squirrel monkeys studied. A comparison of gastric contents from unrestrained and restrained monkeys indicated that restraint significantly increased the free acid concentration. Over a 24-hr period, there was a decrease in volume, free acid and total acid concentration, and pepsin value of the gastric juice. Histamine (0.1 mg/kg hr, subcutaneously) produced a significant increase in free acid and total acid concentration, while the volume and pepsin values were not changed. Methacholine, at cumulative doses of 1.0 and 2.0 mg/kg, subcutaneously, produced a significant decrease in free and total acid concentration while the volume was not altered. Atropine, in cumulative doses of 8, 16, and 48 mg/kg, intraperitoneally, produced a significant fall in volume of gastric juice collected. However, free acid concentration was reduced only at the highest dose and total acid concentration was not changed by any of the doses tested.

Skeletal muscles contain a fraction of free (unesterified) fatty acids. This fraction is very small, but important since it contributes to the creation of the plasma-myocyte free fatty acid concentration gradient. Maintenance of this gradient is necessary for blood-borne fatty acids to be transported into the cell. There are no data on the regulation of the content and composition of the free fatty acid fraction in the cell. The aim of the present study was to examine the effect of an elevation and a reduction in the plasma-borne free fatty acid concentration on the content and composition of the free fatty acid fraction in different skeletal muscle types. The experiments were carried out on male Wistar rats with 280 - 310 g body weight. They were divided into four groups - 1, control; 2, exercised 3 h on a treadmill moving with a speed of 1,200 m/h and set at + 10 degrees incline; 3, treated with heparin; and 4, treated with nicotinic acid. Samples of the soleus as well as the red and white sections of the gastrocnemius muscles were taken. These muscles are composed mostly of slow-twitch oxidative, fast-twitch oxidative-glycolytic and fast-twitch glycolytic fibres, respectively. Lipids were extracted from the muscle samples and from the blood; the free fatty acid fraction was isolated by means of thin-layer chromatography. The individual free fatty acids were identified and quantified using gas-liquid chromatography. The plasma concentration of free fatty acids was as follows: control group, 236.1 +/- 32.9; after exercise, 407.4 +/- 117.5; after heparin, 400.8 +/- 36.8; and after nicotinic acid, 102.5 +/- 26.1 micromol/l (p < 0.01 vs. control values in each case). The total content of the free fatty acid fraction in the control group was as follows: white gastrocnemius, 27.6 +/- 7.3; red gastrocnemius, 52.2 +/- 13.9; soleus, 72.3 +/- 10.2 nmol/g. Elevation in plasma free acid concentration during exercise increased the total content of free fatty acids in the white gastrocnemius (38.7 +/- 13.9) and in the soleus (103.4 +/- 15.9 nmol/g; rest-exercise: p < 0.05 and p < 0.01, respectively), but had no effect in the red gastrocnemius. Neither elevation in the plasma free fatty acid concentration with heparin nor reduction with nicotinic acid affected the total content of the free fatty acid fraction in the muscles examined. The ratio of plasma concentration of individual acid to muscle concentration for the same acid varied greatly, depending on acid, muscle type and experimental group. The ratio was positive (above unity) for each acid almost in all cases with the exception of certain acids in the nicotinic acid-treated group where it was below unity. We conclude that the skeletal myocytes maintain a stable level of free fatty acid fraction in the wide range of plasma free fatty acid concentrations.

Plasma levels of free polyunsaturated fatty acids in patients with ischemic heart disease