Andrea Micaela Dallagnol

Meliponiculture is a practice that involves the keeping of stingless bees (Apidae: Apinae: Meliponini) and the use of their products (Grüter, 2020). While apiculture involves managing the European ...

The composition of extractive organic compounds of seven samples of Tenerife honey is reported here for the first time. In the extractive composition of the studied samples, gas chromatography-mass spectrometry identified between 74 and 124 representatives of various classes of organic compounds, including aromatics, aliphatic acids, alcohols, and esters, as well as furofuran lignans, which are rarely found in honey. The chemical composition of extractives in the studied samples was highly specific: among 160 registered compounds, only forty were present in all seven samples. The most numerous groups, making the greatest contribution to the total ion current of the chromatograms, were formed by aromatic compounds, the main one being methyl syringate. The second most important group consisted of aliphatic acids, including a series of eleven even hydroxy acids C ₈ ‒C ₁₂ , characteristic of royal jelly and largely responsible for its outstanding antimicrobial activity. The high content of compounds with documented biological activity suggests the high therapeutic potential of the studied Tenerife honey samples.

Tenerife’s melliferous flora is characterised by the presence of a large number of endemic species and a distinct zonation of their growth, which determines the local production of unique varieties of honey not found in other parts of the world. For the first time, the composition of volatile organic compounds (VOCs) in Tenerife honey was studied through the use of nine samples of monofloral (broom, tajinaste, tedera, relinchon, and barrilla) and four samples of multifloral honeys. The VOC composition of the studied samples contained 110 representatives of various classes of organic compounds identified by headspace microextraction in combination with gas chromatography-mass spectrometry (GC-MS): terpenes, alkanes and alkenes, aliphatic and aromatic alcohols and acids, carbonyl compounds, as well as several S-, N- and Cl-containing substances. The chemical composition of the samples turned out to be highly specific; only twenty two compounds were detected in all nine samples. The distinct zonation of Tenerife’s honey flora is reflected in the VOC composition of the studied samples. For example, syringic acid hydrazide, a rare component of honey, is completely absent in honey from “high mountain” apiaries but is contained in noticeable quantities in honey from apiaries located at low altitudes. The presence of methyl 3,5-dimethoxybenzoate in Tenerife honeys, as well as some norterpenoids, indicates the likelihood of their high antioxidant and bactericidal activity.

The vegetation of the Canary Islands is characterized by a large number of endemic species confined to different altitudinal levels. It can be assumed that these circumstances determine the characteristic features of the chemical composition of local beekeeping products, including propolis. We report, for the first time, the chemical composition of propolis from Tenerife (Canary Islands). The volatile emissions of three propolis samples collected from different apiaries are represented by 162 C₁–C₂₀ compounds, of which 144 were identified using the HS-SPME/GC-MS technique. The main group of volatiles, consisting of 72 compounds, is formed by terpenoids, which account for 42–68% of the total ion current (TIC) of the chromatograms. The next most numerous groups are formed by C₆–C₁₇ alkanes and alkenes (6–32% TIC) and aliphatic C₃–C₁₁ carbonyl compounds (7–20% TIC). The volatile emissions also contain C₁–C₆ aliphatic acids and C₂–C₈ alcohols, as well as their esters. Peaks of 138 organic C₃–C₃₄ compounds were recorded in the chromatograms of the ether extracts of the studied propolis. Terpene compounds form the most numerous group, but their number and content in different samples is within very wide limits (9–63% TIC), which is probably due to the origin of the samples from apiaries located at different altitudes. A peculiarity of the chemical composition of the extractive substances is the almost complete absence of phenylcarboxylic acids and flavonoids, characteristic of Apis mellifera propolis from different regions of Eurasia and North America. Aromatic compounds of propolis from Tenerife are represented by a group of nine isomeric furofuranoid lignans, as well as alkyl- and alkenyl-substituted derivatives of salicylic acid and resorcinol.

Despite the recent approval of stingless bee honey to the Argentine Food Code, there are still many gaps in information. Likely, the main reason for this is that multiple ecological and chemical factors influence their production and antimicrobial properties. This work combined metabolomic, microbiological, and physicochemical analyses to characterize the honey ofTetragonisca fiebrigifrom Northeastern Argentina. The antimicrobial activity tests showed that honey samples (n = 24) inhibited some Gram-positive and Gram-negative bacteria at different sensitivity levels. Furthermore, samples selected for their high bioactivity revealed crystallizations, a positive correlation with fungal growth, and the presence of flavonoids. The major polyphenols annotated by liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis and supported by metabolomic tools were quercetin 3,4'-dimethyl ether, pachypodol, jaceoside, irigenin trimethyl ether, corymboside, chrysoeriol 7-neohesperidoside, and corymboside. In contrast, samples missing antimicrobial activity did not crystallize, lacked flavonoids, and were enriched in phenylethylamides. Based on these findings, we discuss the significance of flavonoids and phenylethylamides on honey's antimicrobial activity and food quality and how they may indeed reflect essential parameters of the hive, such as microbial balance and eubiosis.

The consumers’ demand for food with high nutritional quality and free of chemical additives increases the need to look for new products and preservation strategies. Quinoa (Chenopodium quinoa) is an Andean pseudocereal highly appreciated because of its nutritional properties. Moreover, it is an optimal substrate for growing and production of improved amounts of antifungal compounds by Lactobacillus plantarum CRL 778. The aim of this work was to optimize a lactic ferment for packaged breads with improved nutritional value and prolonged shelf life by applying a statistical experimental design model. The addition of 30 % quinoa to the wheat semiliquid ferment (QWF) could highly improve the amino acids release (4.3 g/L) during fermentation. Moreover, this quinoa proportion was sufficient to obtain the same concentration of the antifungal compounds, phenyllactic and hydroxiphenyllactic acids (PLA and OH-PLA) as with 100 % quinoa (ca. 36 and 51 mg/L, respectively). Statistical model analysis showed that citrate and skimmed milk enhanced significantly all evaluated parameters specially PLA (ca. 71 mg/L), HO-PLA (ca. 75 mg/L), and lactate (27 g/L) with a p value <0.005. The synergic effects of higher antifungal compounds production, acid release, and pH decrease allowed lowering the amount (about 50 %) of the chemical preservative calcium propionate commonly added to bread. Moreover, these breads show increased shelf life.