The microbiological quality of honey obtained from different processing points and the environmental quality within honey houses were assessed in the Pampas Region (Argentina). Mold and yeast (MY), culturable heterotrophic mesophilic bacteria (CHMB), the number of spore-forming bacteria as well as the presence of Shigella spp., Salmonella spp. and fecal coliforms were evaluated in 163 samples. These samples were taken from eight honey houses. Results showed that 89 samples had ≤10CFU of MY/g honey, 69 ranged from 10 to 50CFU/g and two reached 65.5CFU/g. Eighty one percent of the samples showed ≤30CFU of CHMB/g honey and only seven samples had between 50 and 54.25CFU/g. Thirty six honey samples were obtained from drums: in 25 samples (69.4%) CHMB counts were less than ≤30CFU/g of honey; in 20 samples (55.5%) the values of MY were between 10 and 50CFU/g honey and total coliforms were only detected in 20 samples. Fecal coliforms, spores of clostridia as well as Salmonella spp. and Shigella spp were not detected and less than 50 spores of Bacillus spp. per g were observed in the honey from drums. Therefore, the microbiological honey quality within the honey houses did not show any sanitary risks. Our results were reported to honey house owners to help them understand the need to reinforce proper honey handling and sanitation practices.

The “alperujo” is a waste from the olive oil industry with great potential for valorization. It has a high organic load, with the presence of valuable compounds such as biophenols and sugars. The use of this waste can be thought of as a biorefinery from which different compounds of high added value can be obtained, whether they are present in the “alperujo” such as biophenols or can be generated from the “alperujo”. Therefore, the production of carotenoids by Rhodotorula mucilaginosa was evaluated using the liquid fraction of ‘alperujo’ (Alperujo Water, AW) or an aqueous extract (AE) of “alperujo” at different concentrations (5, 10, 20 and 30% w/V) as substrates. The AEs had an acidic pH, a total sugar concentration ranging from 1.6 to 7.6 g/L, a polyphenols content from 0.4 to 2.9 g/L and a significant amount of proteins (0.5–3 g/L). AW is similar in composition as 30% AE, but with a higher amount of total sugars. Rh. mucilaginosa was able to grow at the different mediums with consumption of glucose and fructose, a reduction in protein content and alkalinization of the medium. Maximum total carotenoid production (7.3 ± 0.6 mg/L) was achieved at AW, while the specific production was higher when the yeast grew at AW or at 30% AE (0.78 ± 0.06 and 0.73 ± 0.10 mg/g of biomass, respectively). Torulene and torularhodin were the main carotenoids produced. Polyphenol content did not change; thus, it is still possible to recover these compounds after producing carotenoids. These results demonstrate the feasibility of using alperujo-based mediums as cheap substrates to produce torularhodin and torulene and to include this bioprocess as a step in an integral approach for alperujo valorization.

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