https://hdl.handle.net/10259/4244 2026-05-11T12:23:26Z 2026-05-11T12:23:26Z Souza, Vanessa Rios de Illera Gigante, Alba Ester Keener, Kevin M. https://hdl.handle.net/10259/11350 2026-02-11T01:05:37Z 2022-08-01T00:00:00Z

High voltage atmospheric cold plasma technology as a food safety intervention for decontamination of cutting tools during ready-to-eat poultry meat slicing Souza, Vanessa Rios de; Illera Gigante, Alba Ester; Keener, Kevin M. This study aimed to build a prototype that integrates a cold plasma capability into a manual meat slicer while it is in operation to minimize cross-contamination from the circular cutting blade. A high voltage atmospheric cold plasma (HVACP) generator was attached to a meat slicer with a rotating 22.5-cm diameter stainless steel slicing blade. The meat slicer with the installed cold plasma generator was contained within a sealed, clear acrylic box. Listeria innocua (LI) was selected as the test organism, and initial testing was performed on stainless-steel coupons in room air at a relative humidity ranging from 30 to 90% for treatment times up to 240 s. Results found that 240 s and 90% RH showed a 3.0-log reduction of LI. These conditions were then replicated using “dirty” stainless-steel knife while rotating. The results showed only a 0.5-log LI reduction. The gas was changed from air to MA65 gas blend (65% O2, 30% CO2 and 5% N2) and then a 1.91 log LI reduction was achieved on the “dirty” knife. Industrial relevance Due to the rapid processing speeds required in the food industry, it is difficult to assure the complete cleanliness of the tools and surfaces used at all times, and then, operations like the cutting /slicing step are still one of the critical points for cross-contamination during meat processing. High voltage atmospheric cold plasma (HVACP) is a practical intervention that has the potential to deliver a continuous, in-situ decontamination of the knife during operation to mitigate the risk of cross-contamination. The developed prototype, as shown in this study, can deliver beneficial results in short treatment time and with minimal inputs of air and electricity, without heating effects, minimizing the use of water, or the use of sanitizers.

2022-08-01T00:00:00Z Illera Gigante, Alba Ester Beltrán Calvo, Sagrario Sanz Díez, Mª Teresa https://hdl.handle.net/10259/11349 2026-02-11T01:05:37Z 2020-07-01T00:00:00Z

Enzyme inactivation and changes in the properties of cloudy apple juice after high‐pressure carbon dioxide and thermosonication treatments and during refrigerated storage Illera Gigante, Alba Ester; Beltrán Calvo, Sagrario; Sanz Díez, Mª Teresa High-pressure carbon dioxide and thermosonication technologies were applied to cloudy apple juice to determine their effect on polyphenol oxidase (PPO) and pectin methylesterase (PME) activity and other quality parameters right after the treatment and during storage at 4ºC for 28 days. Treatment conditions were 20 MPa, 45ºC, for 60 min and 20 kHz, 62ºC, 100% amplitude for 20 min, for pressurized CO2 and thermosonication treatments, respectively. Both treatments showed a great impact on PPO activity and its residual activity steadily decreased during storage at 4ºC. In contrast, PME was found to be more resistant to the treatments. After both treatments, a homogenization effect was observed, which was also reflected in an increase in the cloud value of the juices after the treatments, kept during storage. Antioxidant capacity and total polyphenol content kept high levels during storage after both treatments.

2020-07-01T00:00:00Z Cavia Saiz, Mónica Gerardi, Gisela Muñiz Rodríguez, Pilar García Tojal, Javier Salazar Mardones, Gonzalo https://hdl.handle.net/10259/11151 2026-03-08T23:42:11Z 2025-06-01T00:00:00Z

New approach using alternative proteolytic enzymes to the conventional enzyme pronase for the isolation of bread melanoidins Cavia Saiz, Mónica; Gerardi, Gisela; Muñiz Rodríguez, Pilar; García Tojal, Javier; Salazar Mardones, Gonzalo Bread melanoidins are melanoproteins classically extracted with the proteolytic enzyme pronase E (S. griserus). In this study, the structure and functionality of melanoidins extracted with the proteolytic enzymes papain (PE) and enzymes from B. subtillus (SP) and a mixture from B. subtillus and A. oryzae (MP) were evaluated. PE extracted melanoidins have the highest nitrogen (4.3 %) and protein (29 %) content. FTIR showed that PE had a higher protein content and pronase had higher in carbohydrates. The K420 and K345 values and antioxidant capacities of the PE extract were similar to pronase and higher than the other microbial enzymes. After in vitro digestion, the increased in the antioxidant capacity was most pronounced in the PE extract. No neurotoxicity was observed, as evidenced by no neuronal cell death or changes in neuronal ROS levels. These results indicate that the PE enzyme may be a good alternative to pronase for extraction of melanoidins.

2025-06-01T00:00:00Z Candela Gil, Helena Illera Gigante, Alba Ester Barea Gómez, Pedro Beltrán Calvo, Sagrario Sanz Díez, Mª Teresa https://hdl.handle.net/10259/10917 2025-10-03T00:05:23Z 2025-06-01T00:00:00Z

The Study and Optimization of the AlCl3/SnCl2 Catalyst System in the Subcritical Water Production of Lactic Acid from Corn Stover Candela Gil, Helena; Illera Gigante, Alba Ester; Barea Gómez, Pedro; Beltrán Calvo, Sagrario; Sanz Díez, Mª Teresa The lactic acid (LA) production from corn stover using Lewis acid catalysts was optimized. Initially, an equimolar mixture of Al(III)/Sn(II) was used as a catalytic system at 190 ◦C with 5 wt% biomass. Increasing the catalyst concentration led to higher LA production, showing the optimal results at 16 mM. A low catalyst concentration mainly produced furfural and HMF, dehydration products from the corn stover sugars. Higher catalyst concentration increased LA yield but also produced the degradation of the glucose dehydration products into levulinic and formic acids, reducing LA selectivity. Al(III) was essential for LA formation, while Sn(II) was less effective due to its lower solubility, shown by the presence of Sn(II) in the solid residue after treatments. A total of 16 mM Al(III) yielded the highest LA levels at 190 ◦C, 7.4 g/L, and 20.7% yield. Increasing the temperature to 210 ◦C accelerated the LA production while also achieving the lowest energy consumption, which was 0.47 kWh/g LA at the highest LA production point. However, longer treatments at this temperature caused LA degradation. AlCl3 has been identified as an ideal catalyst for biomass conversion to LA, being inexpensive and low in toxicity.

2025-06-01T00:00:00Z