The Effect of Pretreatments on the Physical Properties and Starch Structure of Potato Chips Dried by Microwaves under Vacuum

Mozzarella cheese snacks produced by microwave vacuum drying: Protein profile, protein digestibility, flavor, and texture

This study investigated the microwave vacuum drying (MWVD) of low-moisture part-skim mozzarella cheese and its impact on protein quality, aroma profile, and texture. Cheese snacks showed a high protein content, corresponding to more than 50% of their dry matter. The MALDI-TOF analysis identified a similar protein profile before and after drying, indicating no structural modifications. Moreover, MWVD did not impact the in vitro protein digestibility of cheese, approximately 87-88%. On the other hand, the natural volatile profile of mozzarella cheese was changed. Aromatic compounds related to fruity flavors (alcohols and esters) were lost during the process; however, the drying favored increasing the content of compounds that contribute vinegary (acetic acid), buttery (acetoin), and sweet (toluene) odor to the product. MWVD also resulted in expanded cheese structures. Consequently, irregular acoustic-mechanical curves were obtained, characteristic of crispy products. Therefore, MWVD is a promising technology for producing high-nutritional quality cheese snacks.

Study on the effect and mechanism of gelatinization-retrogradation pretreatment on the digestibility of potato flour

This study aimed to investigate the effects of gelatinization-retrogradation pretreatment on the slowly digestible starch content and structure of potato flours and the underlying mechanisms. Samples were prepared by microwave gelatinization and low-temperature retrogradation. The slowly digested starch content of medium-low gelatinization potato flour after retrogradation (40.82 %) was 25.55 % higher than that of raw flour. Various testing techniques showed that the relative crystallinity of medium-low gelatinization potato flour after retrogradation was 13.92 %, ΔH = 7.10 J/g. Moderate molecular ordering and thermal stability were the most favorable for the formation of slowly digestible starch, an imperfect crystallization. The microstructure, particle size distribution, and hydration properties showed that the starch granules of medium-low gelatinized samples were partially fragmented and tended to have moderate ordering and thermal stability. This contributed to the slow invasion of the enzyme, while the retained crystalline nuclei facilitated retrogradation. In addition, the slowly digestible starch contents from potato starch and potato flour with broken cell wall (24.50 % and 30.47 %, respectively) were less than potato flour with intact cell structure. The cell wall structure confined free starch, facilitating the recrystallization of starch molecules. Overall, the potato flours produced herein are suitable for the production of slowly digesting products.

Bioactive Compounds and Sensory Quality in Chips of Native Potato Clones (Solanum tuberosum spp. andigena) Grown in the High Andean Region of PERU

Native potatoes (Solanum tuberosum spp. andigena) have diverse pigments and are cultivated in Peru's high Andean regions; they are characterized by containing bioactive compounds that prevent various degenerative diseases. The study aimed to evaluate the physicochemical and sensory quality in chips of native potato clones grown at 3496 m altitude, for which the potatoes were cut into slices and fried in extra virgin olive oil at 180 °C for 200 s. This was determined by proximal analysis, reducing sugars, minerals, color, antioxidant capacity (AC), total phenolic compounds (TPC), and anthocyanins in fresh and chips; an instrumental characterization by FTIR and SEM and sensory tests were also performed. The native potatoes presented low moisture and reduced sugar contents; when frying, their bioactive properties improved, increasing AC, TPC, and trace elements, such as K, Mg, Ca, P, Fe, and Zn. To conclude, fresh clones have high yields in the field and are an essential source of nutrients and bioactive; the salt-free chips of clone B presented better physicochemical properties and greater sensory acceptance, closely followed by clone A. Both clones could be used as raw material by food companies that produce snacks to benefit high Andean agricultural producers.

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.