Pre-dehydration treatments and quality of processed potatoes during storage

ABSTRACT The aim of this work was to study pre-dehydration treatments to maintain consumption quality of processed potatoes (Solanum tuberosum) over a long storage period. Tubers of the cultivars Asterix, Macaca and Agata were cut into cubes and submitted to the following pre-dehydration treatments: water (control), blanching, and blanching with different doses of sodium metabisulfite. Sulphur dioxide residue and microorganism detection were determined right after the dehydration process was completed. Water activity, color, rehydration ratio, cooking time and rehydration ratio after cooking were determined at the beginning and after one and two years of storage. Blanching, cultivar and storage affected rehydration ratio, an important parameter used to measure the quality of dehydrated products. Tubers with higher dry mass content resulted in lower water activity and rehydration ratio, longer cooking time and higher rehydration ratio after cooking than those with lower dry mass. The combination of blanching with sodium metabisulfite improves product quality, reduces microbial load, enhances dehydration rate and prevents oxidation and browning reactions during processing and storage. The effects of the structural damages of pre-dehydration and dehydration treatments on the rehydration ratio and the rehydration ratio after cooking increase with storage of processed potatoes.

High-Pressure Processing and Ultrasonication of Minimally Processed Potatoes: Effect on the Colour, Microbial Counts, and Bioactive Compounds

HPP at 600 MPa alone, and in combination with US at 20 kHz (200 W), was applied to minimally processed potatoes of two commonly grown cultivars in Ireland. Changes in colour and microbial load (Enterobacteriaceae, total aerobic count, Salmonella, yeasts, and moulds) were monitored in vacuum-packaged potatoes during 14 days of storage at 4 °C. HPP and HPP/US significantly (p < 0.05) affected the colour parameters a*, b*, L*, and ΔE of minimally processed potatoes compared to the controls. Microbial growth was delayed in most of the treated samples with respect to those untreated (controls), while HPP completely inactivated Enterobacteriaceae in both cultivars. Total phenolic content and antioxidant activities were not altered in the treated samples of both varieties when compared to the controls. The levels of chlorogenic acid, ferulic acid, and caffeic acid were decreased after both treatments, with a significant (p < 0.05) increase in quinic acid in the treated samples as opposed to those untreated. A significant (p < 0.05) decrease in the levels of glycoalkaloids, namely α-chaconine and α-solanine, in HPP- and HPP/US-treated potatoes was also observed. These findings suggest that HPP and US can extend the shelf-life of minimally processed potatoes with a negligible impact on their antioxidant activity and phenolic content.

Effect of boiling on classification performance of potatoes determined by computer vision

The aim of this study was to evaluate the effect of potato boiling on the correctness of cultivar discrimination. The research was performed in an objective, inexpensive and fast manner using the image analysis technique. The textures of the outer surface of slice images of raw and boiled potatoes were calculated. The discriminative models based on a set of textures selected from all color channels (R, G, B, L, a, b, X, Y, Z, U, V, S), textures selected for color spaces and textures selected for individual color channels were developed. In the case of discriminant analysis of raw potatoes of cultivars ‘Colomba’, ‘Irga’ and ‘Riviera’, the accuracies reached 94.33% for the model built based on a set of textures selected from all color channels, 94% for Lab and XYZ color spaces, 92% for color channel b and 92.33% for a set of combined textures selected from channels B, b, and Z. The processed potatoes were characterized by the accuracy of up to 98.67% for the model including the textures selected from all color channels, 98% for RGB color space, 95.33% for color channel b, 96.67% for the model combining the textures selected from channels B, b, and Z. In the case of raw and processed potatoes, the cultivar ‘Irga’ differed in 100% from other potato cultivars. The results revealed an increase in cultivar discrimination accuracy after the processing of potatoes. The textural features of the outer surface of slice images have proved useful for cultivar discrimination of raw and processed potatoes.

Nutritional Implications of Trade-Offs Between Fresh and Processed Potato Products in the United Kingdom (UK)

The UK ranks eleven among world potato producing countries with annual per capita production of about 102 kg. Since 2007, the price of potatoes has increased by 44 per cent and UK households have shown a decreasing trend on their purchases of potatoes. At the same time, retailers and manufacturers have been introducing processed potato products, which also has affected the demand for fresh potatoes. This has shifted demand from fresh potatoes to processed potatoes suggesting that consumers substitute fresh potatoes for processed ones. However, the extent to which this affect individual weekly nutritional composition is unknown. The objective of this study is to estimate the nutritional trade-offs between fresh and processed potatoes consumed in the UK using home scanner panel dataset for Great Britain in 2018. Price and expenditure elasticities were estimated using the linearized version of the Exact Affine Stone Index (EASI) Demand System. Using estimated elasticities, we analyzed the implications of substituting fresh potatoes for processed potatoes on nutrient intake. The results, in terms of the degree of substitution between fresh potatoes and processed potato products, suggest that consumers consider new potatoes baby and baking potatoes as substitutes for mashed potatoes. Maris piper potatoes and new potatoes baby are substitutes for frozen chips and other potatoes whilst white old potatoes and other vegetables and salads are complements to frozen chips and other potatoes. Finally, price reductions in the processed potatoes will increase average weekly caloric intake as well as the intakes of saturated fat and sodium. The latter has implications for public health as they are the major causes of cardiovascular diseases and certain cancers.

Optimization of processing parameters to control Maillard browning in ready-to-eat processed potatoes

Relationship among pH, aw and Maillard browning was investigated in processed potatoes ready-to-eat during cooking and sterilization in autoclave to prevent their colors changes. Central composite rotational design was used for optimization of color (L*, a* and b*), browning index and intermediate compounds index. Reduction in the L* value and increase in the a*, b* value and browning index, indicators for Maillard browning of the processed potatoes were mitigated at pH 4.0–5.0 and aw 0.96–1.00 and accelerated at pH less than 3.0 or more than 7.0 and aw less than 0.84. Formation of intermediate compounds was intensified at pH 5.0 and aw 0.99 and mitigated at pH 7.0 and aw 0.84. Adjustment of the pH to 5.0 and keeping aw at to 0.99 were the most effective parameters of to control Maillard browning in processed potatoes ready-to-eat.

industrialization of potatoes and the socioeconomic development of family farming in Lima, Peru

Objectives: To analyze the factors that influence the industrialization of the potato and its role as an innovation for the socioeconomic development of small family farming in Lima, Peru. Methodology: This study is based on different information sources from public organizations in Peru to show that the industrialization of potatoes in Lima, Peru contributes to the socioeconomic development of family farming. On this basis, recommendations are made for a business model through cooperatives oriented mainly to family farming. Results: The determining factors that influence the industrialization of potatoes in Lima are, the use of certified seed and varieties suitable for processing, compliance with good agricultural practices in potato farms and the permissible limits of presence of agrochemicals in the tuber, the adaptation to the normative framework of DL 1062 Food Safety Law, allowing to enter a market that demands food with sanitary guarantee, which can be achieved through a cooperative organization of farmers. Conclusions: The industrialization of potatoes constitutes a business opportunity to increase the supply of processed potatoes through cooperatives, generating added value for small fresh potato producers in Lima.