Croatian produced unifloral honey characterized according to the protein and proline content and enzyme activities

Abstract

A b s t r a c t In honey, the content of proteins, including the enzymes, is relatively low and has a minor nutritive significance. On the other hand, the proteins, including the enzymes, are usually used as honey quality evaluation parameters. This is because protein content and enzyme activities vary regarding the botanical origin of the honey. Since the results of protein content, glucose-oxidase, and acid phosphatase, for honeys produced in Croatia, are not available, four of the most abundant honey types produced in Croatia (black locust, sage, chestnut, and honeydew honey) are characterised according to the protein and proline content and enzyme activities. The characterisation was done to determine specificities and contribute to the characterisation of unifloral honeys. Dark honey types (honeydew and chestnut honey) had a higher proline content, and diastase, invertase, and glucose-oxidase activity than lighter sage and black locust honey. Black locust honey has a naturally low enzyme activity and showed the highest acid phosphatase activity among the analysed honey types, while honeydew honey, otherwise known to possess high proline content and enzyme activity, had a low protein content comparable to black locust honey. Statistically significant correlations were obtained between all analysed parameters, with the exception of acid phosphatase activity.

Glucose oxidase activity and hydrogen peroxide accumulation in Croatian honeys

“…Chestnut, lime, honeydew and mint honeys possessed statistically similar (p < 0.05) high GOX activity (341.26 ± 128.78, 350.16 ± 124.91, 376.82 ± 69.02, 402.47 ± 60.99 µg H 2 O 2 /h g, respectively), while black locust honeys approximately 10-fold lower activity (25.58 ± 21.87 µg H 2 O 2 /h g) ( Table 2). Flanjak et al (2016a) have reported similar values for the GOX activity in chestnut, honeydew and black locust honeys. Once the presence of endogenous the GOX activity in examined honeys was confirmed, the effect of honey dilution on hydrogen peroxide accumulation was investigated.…”

“…Glucose oxidase activity in honey was determined by horseradish peroxidase/o-dianisidin method as previously described by Flanjak et al (2016a).…”

Investigation of Variations of Invertase and Glucose Oxidase Degrees against Heating and Timing Options in Raw Honeys

“…Strelec et al [21] used 20 honey samples which were not defined as raw honey and they reached the mean of glucose oxidase values ranging from 25.58 to 402.47 μg H 2 O 2 /h·g. Also, Flanjak et al [14] observed the mean of glucose oxidase of 45 studied honey samples as 40.3-347.6 μg H 2 O 2 /h·g. According to another study, the average value of 57 blossom honey samples tagged as acacia (n � 15), wildflower (n � 32), and rapeseed (n � 8) were found as 29.7 μg/g [22].…”

“…Determination of Glucose Oxidase Activity. Glucose oxidase activity in honey was determined by the horseradish peroxidase/o-dianisidine method as previously described by Flanjak et al [14]. Glucose oxidase catalyzes the oxidation of D-glucose to D-gluconolactone and subsequent transformation to gluconic acid and hydrogen peroxide (H 2 O 2 ).…”

Free amino acid profiles of honey samples from Vojvodina (Republic of Serbia)

“…In addition, it is suggested as an indicator of adulteration of honey with sugars, because its content is lowered in sugar adulterated honeys (Bogdanov and Martin, 2002). The minimum level of 180 mg/kg for proline was internationally accepted for most of the honey types which were not adulterated (Hermosín et al, 2003), except locust honey known to possess low proline content (Flanjak et al, 2016).…”