Kinetics of Colour Development during Frying of Potato Pre-Treated with Pulsed Electric Fields and Blanching: Effect of Cultivar

Impact of cooking on the protein quality of Russet potatoes

Despite being low in crude protein, on a fresh weight basis, given their overall contribution to the North American diet, potatoes contribute approximately 2%-4% of the population's protein intake. However, the quality of the protein remains ill-defined. To that end, Russet potatoes were secured and subjected to various cooking conditions (raw [control], boiled, baked, microwaved, and fried [3, 6, and 9 min]) to determine the impact of cooking method on protein quality, as determined by amino acid score (AAS) and indices of in vivo true fecal protein digestibility (TFPD%; rodent bioassay) and in vitro protein digestibility (pH-drop, pH-Stat, and simulated gastrointestinal digestion both static and dynamic). The AAS of raw Russet potatoes was 0.67 ± 0.01, with histidine being the limiting AA. Frying led to a significant reduction in the AAS, however, other cooking methods yielded similar results to the raw control. The TFPD% of raw potato was low (40.5% ± 3.9%) and was significantly enhanced to over 80% with all cooking methods. Similar patterns were observed with all in vitro measures, however, all methods yielded higher values for the raw control samples. Final protein digestibility-corrected AAS (PDCAAS; product of AAS and TFPD%) values ranged from 0.27 (raw) to a high of 0.57 (boiled), with cooked values being comparable to other plant-based protein sources, including grains, and some nuts and pulses. In vitro PDCAAS values followed similar trends. This study defined the protein quality of cooked Russet potatoes and provides data for use in defining the quality of total protein consumed in the North American diet.

The influence of conventional and novel blanching methods on potato granules, phytochemicals, and thermal properties of colored varieties

Introduction

Colored potatoes comprise many bioactive compounds that potentially support human health. Polyphenols present in them have associated therapeutic benefits like antimutagenic and anticarcinogenic properties.

Method

The current study aimed to explore the effects of different blanching methods (steam blanching, hot water blanching, and microwave-assisted blanching) on the phytochemical and structural aspects of PP-1901 and Lady Rosetta (LR) potato varieties. Changes in the antioxidant activity, color, total ascorbic acid, phenolic, and flavonoid content were based on the variations in parameters including temperature (blanching using hot water and steam) and capacity 100- 900 W (blanching using microwave).

Results

For both PP-1901 and LR varieties, all the blanching methods led to a significant reduction in residual peroxidase activity, as well as affecting their color. The preservation of bioactive substances exhibited a microwave steam>hot water blanching trend. Blanching significantly increased the antioxidant activity of all the samples. Additionally, Fourier-transform infrared spectroscopy revealed that phytocompounds were retained to their maximum in microwave-blanched samples, especially at 300 W. The type of blanching method significantly affected the thermal properties of potatoes by disrupting the ordered structure of the matrix.

Discussion

Microwaves at 300 W can be used as a novel and suitable alternative technique for blanching potatoes, which successfully retained the original quality of it in comparison to steam and hot water blanching.

Multiobjective Optimization of a Frying Process Balancing Acrylamide Formation and Quality: Solution Analysis and Uncertainty Propagation

In this study, we performed multi-objective model-based optimization of a potato-frying process balancing between acrylamide production and a quality parameter (yellowness). Solution analysis revealed that, for most of the Pareto solutions, acrylamide levels exceeded the EFSA recommendation. Almost equivalent optimal solutions were found for moderate processing conditions (low temperatures and/or processing times) and the propagation of the uncertainty of the acrylamide production model parameters led to Pareto fronts with notable differences from the one obtained using the nominal parameters, especially in the ranges of high values of acrylamide production and yellowness. These results can help to identify processing conditions to achieve the desired acrylamide/yellowness balance and design more robust processes allowing for the enhancement of flexibility when equivalent optimal solutions can be retrieved.