Exploratory Monitoring of the Quality and Authenticity of Commercial Honey in Ecuador.

Honey is one of the oldest sweetening foods and has economic importance, making this product attractive to adulteration with cheap sugars. This can cause a critical problem in the honey industry and a possible health risk. The present work has the aim of evaluating the authenticity of honey commercialized in two different provinces of Ecuador (Pichincha and Loja) by performing physicochemical and spectroscopic analyses. For this study 25 samples were collected from different places and markets and characterized by water, sucrose, reducing sugars and electric conductivity measurement. Also, their Raman and Infrared (IR) spectra were recorded and analysed using a Principal Component Analysis (PCA) in order to verify the quality of the honeys. In addition, a screening of several pesticides was performed in order to verify possible chemical threats to human health and honey bees. It was found that 8 samples have a deviation from the Standard established parameters. Two of them have a high difference in the content of sucrose and reducing sugars, which are located deviated from all the other samples in the PCA of the applied vibrational spectroscopy (IR/Raman), shaping two clear clusters. The results show that Raman and IR spectroscopy is appropriate techniques for the quality control of honey and correlates well with the physicochemical analyses.

Sensory evaluation of cakes prepared with orange-fleshed sweet potato flour (Ipomoea batatas L. ) / Evaluación sensorial de pasteles con harina de camote (Ipomoea batatas L. )

Objective: to assess students´ acceptability and preference for cakes prepared with orange-fleshed sweet potato flour (Ipomoea batatas L.). Materials and methods: the cakes were prepared with wheat flour (sample A) and a mixture where 40% of the wheat flour was replaced by orange-fleshed sweet potato flour (sample B). Questionnaires were applied to 100 students between 10 and 12 years old from a public school in the city of Rio de Janeiro; sensory acceptance and preference tests were also applied. Results: participants were on average 11,7 years old, 80% were 6th graders, 50% were female and 97% of the students reported liking the cakes. In this group, 14% reported consuming cakes less than once a month; 27%, 1-3 times per month; 37%, 1-4 times per week; 19%, 1-2 times a day; and only 2% reported never consuming them. Both cakes had high acceptability; with an average score of 9,27 (A) and 9,26 (B) out of a maximum of 10, without any significant differences in preference. Cake consumption was part of the children´s eating habits. Conclusions: cakes prepared with 40% sweet potato flour were as well accepted as conventional cakes. Further, a portion of this cake (60 g) can contribute up to 22% of daily vitamin A needs. Key words: sweet potato (Ipomoea batatas L.), food fortified, food analysis, sensory evaluation, consumer satisfaction, food preferences.

Objetivo: evaluar la aceptabilidad y preferencia de los estudiantes por los pasteles preparados con harina de camote (Ipomoea batatas L.). Materiales y metódos:los pasteles fueron preparados con harina de trigo (muestra A) y una mezcla donde se reemplazó el 40% de la harina de trigo por harina de camote (muestra B). Se aplicaron cuestionarios a 100 estudiantes entre 10 y 12 años de edad de una escuela pública en la ciudad de Río de Janeiro, a quienes se les aplicaron pruebas sensoriales de aceptación y preferencia. Resultados:los participantes tenían en promedio 11,7 años, 80% cursaban sexto grado, 50% eran mujeres y el 97% de los estudiantes reportaron gustarles los pasteles. En este grupo, 14% informó que consumían los pasteles menos de una vez al mes, 27%, 1-3 veces al mes, 37%, 1-4 veces por semana, 19%, 1-2 veces al día y sólo un 2% informó no consumirlos. Ambos pasteles tuvieron una alta aceptación, con puntuación media de 9,27 (A) y 9,26 (B) de un máximo de 10 sin diferencias significativas en la preferencia. El consumo de pasteles fue parte de los hábitos alimentarios de estos niños. Conclusiones: pasteles elaborados con 40% de harina de camote podría tener tan buena aceptación como los convencionales. Además, una porción de este pastel (60 g) puede alcanzar hasta 22% de las necesidades diarias de vitamina A.

Degradation of cell wall materials from sweetpotato, cassava, and potato by a bacterial protopectinase and terminal sugar analysis of the resulting solubilized products.

Cell wall materials (CWMs) from sweetpotato, cassava, and potato starch residues were degraded using a crude enzyme solution from the culture filtrate of a Bacillus sp. isolated from soil, Bacillus sp. M4. This organism has been found to secrete polygalacturonic acid lyase (PGL) and glycan depolymerase activities, especially arabinanase, but cellulase activity was nearly absent. Sugar analysis of the solubilized product after enzyme treatment at pH 7.0 revealed that it is mainly composed of galacturonic acid, galactose, and arabinose, the sugars found commonly in the pectin fraction. This suggested the presence of a protopectinase (PPase) activity in the culture filtrate. The presence of EDTA completely inhibited PGL but PPase activity was almost retained, suggesting that the PGL is not the primary activity responsible for pectin solubilization. The mode of action of the crude enzyme was determined by terminal sugar analysis using HPAEC-PAD after hydrolysis of the reduced products. Results revealed that galactose is the main neutral sugar at the reducing terminal of the products, although rhamnose was also present in the higher molecular weight component. This suggested that at neutral pH, the primary activity in the culture filtrate of Bacillus sp. M4 is a B-type PPase, which attacked the galactan as well as rhamnogalacturonan moieties of the protopectin, resulting in the release of a soluble pectin fraction.