Multivariate evaluation of the printing process on 3D printing of rice protein.

The combination of printing parameters appropriately improves the printability of 3D-printed foods. In this regard, the present study aims to evaluate the effect of 3D printing process parameters on protein food generation. Printability of a cylinder 3 cm in diameter and 1 cm in height using a protein mixture of rice water and xanthan gum with a ratio of 30:70:0.5 was evaluated in an extrusion printer with an XYZ system. A ½ fractional factorial design was used with three factors: nozzle diameter (1.2 - 2.2 mm), layer height (1.0 - 2.0 mm), and print speed (20 - 50 mm/s). Each combination of factor levels was performed in triplicate for 12 runs plus three central points. Print time (min), sample weight, change in diameter (%), change in height (%), change in volume (%), mass flow rate (mg/s), appreciation (qualitative variable), and textural and rheology characters were obtained as response variables. The linear effects of the factors and combination factors were evaluated by analysis of variance. Additionally, a principal component analysis was performed to visualize the similarity between the observations and the relationship between the variables. The results showed that the layer height and nozzle diameter affect the printing accuracy concerning surface quality, shape stability, resolution, and layer layout. The nozzle with a diameter of 1.7 mm combined with speeds between 35 and 50 mm/s allowed the effects of overextrusion to be overcome, generating a better flow of the material. Low scores in the printability variable were related to low-speed values (20 mm/s) and a high nozzle diameter (2.2 mm), which generated higher deformations in the printed protein cylinder. Additionally, some printing conditions affected the textural and rheological characteristics, which allowed inferring that the capacity of the protein mass to store and recover energy in compression processes is conditioned by the printing parameters.

Exploring the effect of utilising organic acid solutions in ultrasound-assisted extraction of pectin from apple pomace, and its potential for biomedical purposes.

Biomass resulting from food production represents valuable material to recover different biomolecules. In our study, we used apple pomace to obtain pectin, which is traditionally extracted using mineral acids. Our hypothesis consisted of carrying out extractions with organic acids, assisted by ultrasound, by varying processing parameters including time, temperature, and type of acid. The analytical determinations of galacturonic acid content, methoxylation and esterification degree, ζ-potential and extraction yield were used as pectin quality indicators. Pectins extracted using treatment conditions with better performance were assessed biologically in vitro for their potential to be used in biomedical applications. Overall, the extracted pectin presented a galacturonic acid content, methoxylation and esterification degree ranged from 19.7 to 67%, 26.8-41.4% and 58-65.2% respectively, and were negatively charged (-24.1 to -13.2 mV). It was found that factors of time and temperature greatly influenced the response variables excepting the esterification degree, while the acid type influenced the ζ-potential, methoxylation and esterification degrees. Additionally, it was seen that the longer extraction time (50 min) and higher temperature (50 °C) exhibited the better extraction yield (∼10.9%). Finally, the selected pectin showed high cytocompatibility up to 500 µg/mL of concentration when seeded with Neonatal Normal Human Dermal Fibroblasts.

Is the dietary acrylamide exposure in Chile a public health problem?

This study estimates for the first time dietary acrylamide intake in Chile and conducts exposure risk assessments using the margin of exposure (MOE) method. A consumption frequency survey of starchy foods was carried out in the metropolitan region of Santiago, Chile on people from different socioeconomic levels aged between 12 and 65 years old. The acrylamide contents of the most frequently consumed foods were determined by an in-house validated GC-MS technique. The potatoes and bread group contributed ~77% to the dietary acrylamide exposure in Chile, with estimated daily mean exposure of 0.55 µg kgbw-1 day-1 and 0.22 µg kgbw-1 day-1, respectively. Chilean population aged between 12 and 17 years old presented the highest acrylamide intake (mean, 1.27 µg kgbw-1 day-1; 95th percentile, 3.90 µg kgbw-1 day-1). Finally, since the estimated MOEs were lower than 10,000, the dietary acrylamide exposure in the metropolitan region of Santiago, Chile is of public health concern according to the EFSA criteria.

Effect of formulation and heat treatment on 5-hydroxymethylfurfural formation and quality parameters in dulce de leche.

This work assessed the effect of formulation and heat treatment on the formation of HMF, non-enzymatic browning and rheology of dulce de leche (DL). Laboratory scale trials were developed with different DL formulas: whole powdered milk, skimmed milk, and lactose-free skimmed milk, and added sucrose, subjected to different processing temperatures (110°C, 120°C, and 130°C). Additionally, an alternative formulation was designed in which half the sucrose was replaced by 50% tagatose. DL samples were compared with three commercial products in terms of water activity, soluble solids content, pH, colour, apparent viscosity, and HMF concentration. HMF formation in DL was mitigated (35%) in a lactose-free formulation by lowering the process temperature. Moreover, HMF formation was reduced up to 80% replacing sucrose by tagatose without affecting the quality parameters (pH, soluble solids, colour, and apparent viscosity). Decrease in processing temperature and the use of tagatose are viable alternatives for HMF mitigation in DL.