Active coatings of thermoplastic starch and chitosan with alpha-tocopherol/bentonite for special green coffee beans.

The quality of green coffee beans (GCBs) is possibly affected by storage conditions. Edible polymer coatings for GCBs can help preserve flavors and improve shelf life of GCBs. This study aimed to incorporate α-tocopherol, a powerful antioxidant, in thermoplastic starch [TPS] and chitosan [TPC] and determined the best cavitation energy (960-3840 J·mL-1) using an ultrasonic probe. Then, we evaluated the incorporation of bentonite (0% and 2% m/m) and α-tocopherol (0% and 10% m/m) in the best energy cavitation/biopolymer combination. The TPS and TPC coatings demonstrated good adherence to the GCBs, measured by surface energy. The dispersion of α-tocopherol in TPC, with cavitation energy 960 J·mL-1, promoted greater stability (greater zeta potential), thereby increasing antioxidant activity by 28% compared to TPS, therefore, was selected for a second stage. Incorporation of 2% bentonite into the TPC, with 10% α-tocopherol, resulted in a 3.7 × 10-10 g·m-1·s-1·Pa-1 water vapor permeability, which is satisfactory for prevented of moisture gain during storage. The compressive load showed values of 375 N to the non-coated GCB and around 475 N with the insertion of coatings to the GCB. Thus, a TPC/α-tocopherol/bentonite combination, dispersed with 960 J·mL-1 energy, was highly effective in the development of biopolymeric coatings for the GCBs.

Sensory analysis and fatty acid profile of specialty coffees stored in different packages.

The conservation of the quality of special coffees depends on the storage conditions. Therefore, new technologies for the packaging of grains need to be studied. This work was carried out with the objective of evaluating the effect of different packages on the quality of the stored coffee. The free fatty acid profile, fat acidity and sensory characteristics of the grains were analyzed during storage. The coffees were stored for 12 months in 8 packaging types. Coffee stored in jute bags differed mainly due to the higher values of fat acidity and lower scores in sensory analysis. The high-barrier packages were more efficient in the storage of the coffee beans since they presented the lowest deterioration indicators, represented by the low values of fat acidity, free fatty acids and higher scores in the sensorial evaluation.

Raman spectroscopy for the differentiation of Arabic coffee genotypes.

The objective of this study was to evaluate the ability of Raman spectroscopy to identify the genotype of green coffee beans. Four genotypes of Arabic coffee: one Mundo Novo line (G1) and three Bourbon lines (G2, G3, and G4). The harvest was selected using a wet processing method. Raman spectra of the samples were obtained using a FT-Raman RFS/100 spectrometer in the spectral range of 3500-400 cm-1. The data were treated using chemometric unsupervised classification tools and supervised analysis. Using the unsupervised analysis (PCA), the apparent tendency of agglomeration between samples G1 and G3 was verified. These differences were present in the spectral bands that are characteristic of fatty acids and kahweol. Based on this information, a classification model to discriminate (PLS-DA) the Mundo Novo and Bourbon samples was utilized. Raman spectroscopy allowed the building of an adequate model to differentiate between coffee genotypes.

Effect of different ingredients contents on physical, physicochemical and sensory properties of the creamy banana marmalade cv. ‘nanica’(Musa cavendishii)

Banana is a highly perishable fruit, with a shelf life of 7 to 10 days, and the fruits being in excess or those in non conformity to be consumed are used to produce marmalade; and it is an interesting economic alternative. This study evaluated the effect of different ingredients on the physical, physicochemical and sensory properties of creamy banana marmalade. An incomplete factorial design (24-1) with two levels of four factors (pulp/sugarratio, pectin concentration, added amount of acid and sorbate concentration). The sensorial acceptance of marmalades was evaluated using a 9-point hedonic scale, and the purchase intention by employing a 5-pointscale. The analyzed variables mostly affecting the parameters were the pulp/sugar ratio, the added amount of acid and the sorbate concentration, due to their reaction with the marmalade components. The formulation 2 was preferred by consumers because of the firmest texture and the intensified yellow color.