Physicochemical properties of dehydrated potato parenchyma cells with ungelatinized and gelatinized starches

Exploring the mechanism of high hydrostatic pressure on the chemical activity of starch based on its structure and properties changes

High hydrostatic pressure (HHP) could induce changes in the structure and properties of starch. Native corn starch was treated and octenyl succinic anhydride (OSA)-modified corn starch was prepared under different pressures (200, 350, 500 and 600 MPa) at 40℃ for 20 min. The mechanism of HHP on the chemical activity of starch was elucidated by analyzing the relationship between the changes of native starch structure and properties and the quality of OSA-modified starch. Results showed that HHP not only helped water and OSA to penetrate the starch granules but also made the structure of starch granules undergone three changes similar to mechanochemical effects. The starch granules treated by 200 MPa were in the stress stage, and the starch granules treated by 500 MPa were in the transition stage from aggregation to agglomeration. Proper pressure treatment could significantly improve chemical activity of starch and quality of OSA-modified starch.

Transformations and functional role of starch during potato crisp making: A review

Potato chips are a major product in the savory snack market and are consumed worldwide because of their enjoyable and distinctive organoleptic properties. They are conventionally produced by deep-frying thin slices of fresh potato. In contrast, potato crisps are manufactured from dried potato derivatives such as potato flakes (PFs). Their production is reviewed in this manuscript and requires the formation of dough based on hydrated PFs. Expansion of the dough during deep-frying provides the crisps with their desired crunchy texture. As part of an overall trend, the consumer search for calorie-reduced food products has also stimulated research to lower oil uptake during crisp production. However, minimizing oil absorption without losing the characteristic palatability of deep-fried products is challenging and requires fundamental knowledge on factors determining product texture and oil absorption. The transformations and functional role of starch, potato's main constituent, during crisp making are key in this respect and are reviewed here.

Amylose molecular fine structure dictates water-oil dynamics during deep-frying and the caloric density of potato crisps

The fine structure of extractable amylose (E-AM) in potato flakes dictates oil uptake during the production of deep-fried crisps from dough made from the flakes, and thus their caloric density. High levels of short E-AM chains increase the extent of amylose crystallization during dough making and increase water binding. Time-domain proton NMR analysis showed that they also cause water to be released at a low rate during deep-frying and thus restrict dough expansion and, most importantly, oil uptake. X-ray micro-computed tomography revealed that this results in high thickness of the crisp solid matrix and reduced pore sizes. Thus, the level of short E-AM chains in potato flakes impacts amylose crystal formation, dough strength and expansion, as well as the associated oil uptake during deep-frying. Based on these results, we advise potato crisp manufacturers to source potato cultivars with high levels of short amylose chains for the production of reduced-calorie crisps and to make well-reasoned process adaptations to control the extractability of potato amylose.

Isolation and physicochemical property of individual parenchyma cells from mealy sweet potato

This study prepared the dehydrated sweet potato parenchyma cell (SPPC) by isolating intact, individual parenchyma cells (PC) from sweet potato (SP) flesh using pectinase, and compared its chemical compositions, solubility and swelling power, gelatinization, and pasting viscosity to sweet potato starch (SPST) and flour (SPFL). The highest yield of SPPC was achieved when frozen SP whole-tissues were treated with pectin lyase. The majority constituting SPPC was intact, individual PCs fully filled with SPST granules. SPPC possessed lower crude protein and ash contents than SPFL. SPPC revealed lower solubility and swelling power, higher gelatinization temperatures, and lower pasting viscosity than SPST, while it showed lower solubility, higher swelling power, lower gelatinization temperatures, and higher pasting viscosity than SPFL. Overall, SPPC characteristics may result from intact PC walls surrounding clusters of SPPC granules, and SPPC could be considered an alternative to SPFL and SPST for expanding industrial applications of SP.

Potato snacks added with active components: effects of the vacuum impregnation and drying processes

Potato snacks can be used as an ideal strategy for nutrient delivery, since they are one of the most widely consumed products in the world. Due to fried snacks are known to be a significant source of fat intake, consumption is changing towards healthier alternatives. The aim of this research is to evaluate the effect of vacuum impregnation and three dehydration techniques: heated air drying, freeze drying, and microwave vacuum drying of the potato snack that has been fortified with active components: calcium and vitamins C and E. Vacuum impregnation was evaluated using the response surface methodology that had a central composite experimental design with the following independent variables: vacuum pressure, vacuum stage time, and atmospheric stage time. The following were the dependent variables: fraction and volumetric deformation in the vacuum stage and at the end of the process and effective porosity. Finally, a sensorial analysis was carried out on the dehydrated potatoes. The results of the optimal vacuum impregnation process conditions were: a vacuum pressure of 77.3 kPa for 3.0 min followed by 4.0 min at atmospheric pressure. The content of calcium, vitamin C, and vitamin E in the impregnated potato were 956, 472, and 35 mg 100 g^-1 dry solids, respectively. The highest retention of the active components in snacks was obtained by the combination of vacuum impregnation and the dehydration techniques in the following order: freeze drying, microwave vacuum drying, and then heated air drying. It can be concluded that the integration processes give an added value to potato snacks due to the increased content of the active components; additionally, the vacuum impregnation process together with microwave vacuum drying was the alternative that had the highest sensorial acceptability.

Controlled gelatinization of potato parenchyma cells under excess water condition: structural and in vitro digestion properties of starch

The starch digestion rate and extent of potato-based food were modulated through controlled gelatinization.