Sugar Content Of Potatoes Research Articles

Determining the shelf life and quality changes of potatoes (Solanum tuberosum) during storage using electronic nose and machine learning.

The activities of alpha-amylase, beta-amylase, sucrose synthase, and invertase enzymes are under the influence of storage conditions and can affect the structure of starch, as well as the sugar content of potatoes, hence altering their quality. Storage in a warehouse is one of the most common and effective methods of storage to maintain the quality of potatoes after their harvest, while preserving their freshness and sweetness. Smart monitoring and evaluation of the quality of potatoes during the storage period could be an effective approach to improve their freshness. This study is aimed at assessing the changes in the potato quality by an electronic nose (e-nose) in terms of the sugar and carbohydrate contents. Three potato cultivars (Agria, Santé, and Sprite) were analyzed and their quality variations were separately assessed. Quality parameters (i.e. sugar and carbohydrate contents) were evaluated in six 15-day periods. The e-nose data were analyzed by means of chemometric methods, including principal component analysis (PCA), linear data analysis (LDA), support vector machine (SVM), and artificial neural network (ANN). Quadratic discriminant analysis (QDA) and multivariate discrimination analysis (MDA) offer the highest accuracy and sensitivity in the classification of data. The accuracy of all methods was higher than 90%. These results could be applied to present a new approach for the assessment of the quality of stored potatoes.

Development of kinetic models for prediction of reducing sugar content in potatoes using literature data on multiple potato varieties

Reducing sugar (RS) content in potatoes beyond a certain limit leads to browning of chips and the formation of acrylamide (carcinogen). The data for RS vs time at different storage temperatures was collected for 51 potato varieties. Out of these, 16 varieties with RS data available for at least three temperatures were used for development of two models (A and B). Model A consisted of two equations (linear, log) fitted to RS data of entire storage duration for each potato variety and most of these equations had R2adj in the range 0.75–0.95. Model B consisted of a common linear equation form fitted to data of 100 days (where most of the change occurs) with R2 value 0.7–0.98. The activation energy for most of the varieties was in the range of −120 to −300 kJ/mol. Considering the wide variation in the rate of sugar accumulation, potato varieties were categorized as Cold-resistant (CR) and Cold-sensitive (CS) and two separate model equations were developed. These models were validated using data collected through in-house experiments and literature data. The models predicted RS of different potato varieties with Root Mean Square Error of 0.02–3 g/kg FW (Fresh Weight) and Accuracy factor below 1.8.

Effectiveness of a developed potato storage system in shelf life and nutritional quality compared to traditional practice in Bangladesh

This research was carried out to achieve the objective of finding out the performance of a developed potato storage system in storage life and nutritional quality and comparing the system to the traditional practice in Bangladesh. A laboratory version of improved design of potato store and its construction was made at Bangladesh Agricultural University which consisted an evaporative cooling chamber, made of reinforced concrete cement; partially filled-in with water. Two varieties of potato (Diamant and Lal Pakri) were used in this research. Both large and small types for each kind of potato varieties were taken. Experimental design was set up for both improved storage bin and farmer's traditional practice. Spoilage, sprouting, shrinkage, moisture content, vitamin C, and total sugar content of potato were determined for both methods of storage at a regular interval and results were compared. Economic benefit of the developed storage system over traditional practice was also determined. From the result of the study, it appeared that the improved potato storage bin was better in shelf life and nutritional quality for storing potato than the farmer's traditional practice.

The Effect of Paclobutrazol Application Time and Variety on Growth, Yield, and Quality of Potato (Solanum tuberosumL.)

An experiment was set up to investigate the effect of time of paclobutrazol application and variety on growth, yield, and quality of potato in a greenhouse at 34°C (±3) and 21°C (±3) day and night temperatures, respectively, with 60% relative humidity. The experiment was set up as a 2 × 4 factorial design in a CRD with 3 replications. The first factor was potato variety and the levels were BP1 and Diamond. The second factor was paclobutrazol application time and the levels were 28 (Days After Planting) DAP, 35 DAP, and 42 DAP and no paclobutrazol applied (control). Early application of paclobutrazol reduced stem length, number of tubers per plant, and sugar content of potato; furthermore, it increased starch content and yield compared to late application and no paclobutrazol treatments. Early application of paclobutrazol at 28 DAP is recommended in high temperature zones as it increased the yield by 108% and quality of potato.

Evaluation of sugar content in potatoes using NIR reflectance and wavelength selection techniques

Near-infrared (NIR) diffuse reflectance has been extensively and successfully applied on quality assurance for fruits, vegetables, and food products. This study is principally aimed to extract the primary wavelengths related to the prediction of glucose and sucrose for potato tubers (of Frito Lay 1879 (FL), a chipping cultivar, and Russet Norkotah (RN), a table use cultivar, and investigating the potential of classification of potatoes based on sugar levels important to the frying industry. Whole tubers, as well as 12.7mm slices, were scanned using a NIR reflectance spectroscopic system (900–1685nm). To extract the most influential wavelength in the studied range, interval partial least squares (IPLS), and genetic algorithm (GA) were utilized. Partial least squares regression (PLSR) was applied for building prediction models. Prediction models for RN showed stronger correlation than FL with r(RPD) (correlation coefficient (ratio of reference standard deviation to root mean square error of the model)) values for whole tubers for glucose being as high as 0.81(1.70), and 0.97(3.91) for FL and RN; in the case of sliced samples the values were 0.74(1.49) and 0.94(2.73) for FL and RN. Lower correlation was obtained for sucrose with r(RPD) for whole tubers as high as 0.75(1.52), 0.92(2.57) for FL and RN; and the values for sliced samples were 0.67(1.31) and 0.75(1.41) for FL and RN respectively. Classification of potatoes based on sugar levels was conducted and training models were built using different classifiers (linear discriminant analysis (LDA), K-nearest neighbor (Knn), partial least squares discriminant analysis (PLSDA), and artificial neural network (ANN)), in addition to classifier fusion. To obtain more robust classification models for the training data, 4-fold cross validation was used and results were tested using separate sets of data. Classification rates of the testing set for whole tubers, based on glucose, were as high as 81% and 100% for FL and RN. For sliced samples, the rates were 83% and 81% for FL and RN. Generally, lower classification rates were obtained based on sucrose with values of whole tubers of 71%, and 79% for FL and RN, and for sliced samples the rates were 75%, and 82% which follows a similar trend as PLSR results. This study presents a potential of using selected wavelengths and NIR reflectance spectroscopy to effectively evaluate the sugar content of potatoes and classify potatoes based on thresholds that are crucial for the frying industry.

SNPs in genes functional in starch-sugar interconversion associate with natural variation of tuber starch and sugar content of potato (Solanum tuberosum L.).

Starch accumulation and breakdown are vital processes in plant storage organs such as seeds, roots, and tubers. In tubers of potato (Solanum tuberosum L.) a small fraction of starch is converted into the reducing sugars glucose and fructose. Reducing sugars accumulate in response to cold temperatures. Even small quantities of reducing sugars affect negatively the quality of processed products such as chips and French fries. Tuber starch and sugar content are inversely correlated complex traits that are controlled by multiple genetic and environmental factors. Based on in silico annotation of the potato genome sequence, 123 loci are involved in starch-sugar interconversion, approximately half of which have been previously cloned and characterized. By means of candidate gene association mapping, we identified single-nucleotide polymorphisms (SNPs) in eight genes known to have key functions in starch-sugar interconversion, which were diagnostic for increased tuber starch and/or decreased sugar content and vice versa. Most positive or negative effects of SNPs on tuber-reducing sugar content were reproducible in two different collections of potato cultivars. The diagnostic SNP markers are useful for breeding applications. An allele of the plastidic starch phosphorylase PHO1a associated with increased tuber starch content was cloned as full-length cDNA and characterized. The PHO1a-HA allele has several amino acid changes, one of which is unique among all known starch/glycogen phosphorylases. This mutation might cause reduced enzyme activity due to impaired formation of the active dimers, thereby limiting starch breakdown.

Current issues in dietary acrylamide: formation, mitigation and risk assessment

Acrylamide (AA) is known as a neurotoxin in humans and it is classified as a probable human carcinogen by the International Agency of Research on Cancer. AA is produced as by-product of the Maillard reaction in starchy foods processed at high temperatures (>120 °C). This review includes the investigation of AA precursors, mechanisms of AA formation and AA mitigation technologies in potato, cereal and coffee products. Additionally, most relevant issues of AA risk assessment are discussed. New technologies tested from laboratory to industrial scale face, as a major challenge, the reduction of AA content of browned food, while still maintaining its attractive organoleptic properties. Reducing sugars such as glucose and fructose are the major contributors to AA in potato-based products. On the other hand, the limiting substrate of AA formation in cereals and coffee is the free amino acid asparagine. For some products the addition of glycine or asparaginase reduces AA formation during baking. Since, for potatoes, the limiting substrate is reducing sugars, increases in sugar content in potatoes during storage then introduce some difficulties and potentially quite large variations in the AA content of the final product. Sugars in potatoes may be reduced by blanching. Levels of AA in different foods show large variations and no general upper limit is easily applicable, since some formation will always occur. Current policy is that practical measures should be taken voluntarily to reduce AA formation in vulnerable foods since AA is considered a health risk at the concentrations found in foods.

Influence of storage conditions on the sensory and physicochemical characteristics of Galician Kennebec potatoes (Solanum tuberosumL.)

In this study, we compared conventional storage of Kennebec potatoes in a ventilated room at ambient temperature with storage at controlled temperatures of 10, 7 and (initially) 4°C as regards the evolution of colour, hardness, dry matter, pH, vitamin C and sugar contents and sensory properties. The increase in sugar content in potatoes stored at 4°C was so rapid that within 15 days their reducing sugar content exceeded the permitted limit for sale under the EU Protected Geographical Indication label “Pataca de Galicia”. Sugar content also increased at 10 and 7°C, but after 3 months the increase was not sufficient to exceed the specified limit. The sugar content of conventionally stored potatoes remained approximately constant, but these potatoes became softer, flabbier and more wrinkled due to loss of moisture. Overall, storage at 7°C seemed to be the best of the storage conditions tested.

Qualidade de batata para fritura, em função dos níveis de açúcares redutores e não-redutores, durante o armazenamento à temperatura ambiente

Frying quality of potato, with regard to reducing sugar and non- reducing sugar, during storage at room temperature. The present paper aims to determine the reducing sugar and non-reducing sugar content in potatoes (cvs. Atlantic, Asterix, Innovator and Shepody), grown in different doses (0, 120, 360 and 1,080 kg K2O ha -1 ) and sources of potassium (KCl and K2SO4), and stored at room temperature. The samples are from Fazenda Rio Grande, Parana state, Brasil, grown in water crop. The average levels of reducing sugar were 38.10 mg glucose 100 g -1 of potato and non-reducing sugars were 247.90 mg saccharose 100 g -1 of sample. Significant differences were observed in the levels of reducing sugar in the cultivars, source of potassium and storage time. The non-reducing sugars showed statistical differences in all variables. The reducing sugar tended to decrease until 30 days, while there was no significant change in the content of non-reducing sugars for this period. It was concluded that the levels of reducing and non-reducing sugars depend on the cultivar, fertilization (dose and source) and storage time.

Effects of short periods of chilling and warming on potato sugar content and chipping quality

Two days of chilling (exposure to 1 C) had no detectable effect on chip color or sugar content of potato (Solanum tuberosum L.) tubers. Four days of chilling led to increases in sugars if potatoes were stored at 10 C or 19 C for 3 to 4 days after chilling ended. Longer chilling gave increases in sugars by the end of the chilling period, and returning tubers to 10 C or 19 C magnified the response. Glucose and fructose gave similar increases from chilling treatments, except that glucose levels were consistently greater. Sucrose was increased by chilling, but the response pattern did not always resemble that of the reducing sugars. Twenty-seven days of storage at 19 C after chilling lowered levels of reducing sugars late in the storage season but not in December. Cultivars differed in response to chilling. Kennebec tubers accumulated far more reducing sugars but much less sucrose than did Norchip tubers. Storage at 19 C after chilling lowered the sucrose content of Kennebec and Monona while raising that of Norchip.

Clinitest: A simple technique for estimation of reducing sugar content of potatoes

The Clinitest method, originally devised to test urine of diabetic patients, proved to be effective for estimating reducing sugar content of tuber juice. Data obtained by the Clinitest method correlated well with data obtained from the same tubers by the analytical dinitrophenol method and by chip color numbers as determined by Agtron ranges. Simplicity in operation, low cost, and quick results are the main attributes of this method that is potentially useful to the potato industry.

The immediate effect of gamma irradiation upon the sugar content of potatoes previously stored at 2, 4.5, 6, 10 and 15.5°C

The sugar content of samples of potatoes, cv. Majestic, was varied by storage for 4 weeks at 2, 4.5, 6, 10 and 15.5°C, before irradiation with 10 krad. With initial sucrose contents of 0.14–0.37% FW (tubers from 4.5–15.5°C) the marked temporary increase in sucrose, as reported previously, was observed, reaching a maximum after 3–7 days before falling rapidly to a level rather higher than in non-irradiated tubers. Tubers from 2°C, with 1.4% sucrose, showed an immediate drop in this after irradiation, succeeded within 3 days by a rise to values not significantly different from the controls. Irradiation caused a significant increase in reducing sugar content, for a period of up to 7 days in sweetened tubers, but for 21 days or more in unsweetened tubers. Previous storage at the different temperatures had some permanent residual effect upon the sugar content of the controls during subsequent storage for up to 90 days at 10°C.

The apparent effect of the latitude of the place of cultivation upon the sugar content of potatoes grown in Great Britain

Before tuber initiation the content of reducing sugars in the stolon tips was high, the sucrose content was low and the reducing sugar/sucrose ratio was very high. Tuber formation was apparently associated with a rapid fall in this ratio. The content of total sugars was at a maximum (about 1.5–3% fresh weight) 1–2 weeks after tuber initiation, sucrose predominating. There was no correlation between this maximum sugar content and latitude of growth. Sugar content fell as the tubers developed to a final value of 0.1–0.3% total sugars. During this fall, and at maturity, there were usually statistically significant correlations between the distance north of cultivation and the contents of total sugar, sucrose and reducing sugars respectively. There was thus a greater tendency for potatoes grown in the north to be unacceptable for crisp manufacture.

The effects of soil temperature, harvest sequence and storage on French fry processing quality of potatoes

A study was made of the influence of harvest sequence, soil temperature, storage at 10 C and specific gravity on the French fry processing quality ofRusset Burbank andRusset Sebago potatoes grown in four different localities in Wisconsin. Late harvested potatoes contained greater amounts of reducing sugars than early harvested potatoes due to persistent low soil temperatures. The late harvested potatoes were, because of the high reducing sugar content. unsuitable for immediate processing into frozen French fries. Early harvested potatoes, when stored at 10 C developed high levels of reducing sugars and were unsuitable for processing into French fries, even when conditioned at 21 C. Levels of 0.5% or less in reducing sugar content in potatoes were deduced to be essential for acceptable quality in French fries. Generally rating scores of colour, mealiness, and flavor of French fries decreased with continued storage at 10 C of the potatoes from which they were made. Separation of potatoes with higher specific gravity improved scores of lack of oiliness and mealiness.

The effect of γ-irradiation upon the sugar content of potatoes

Potatoes irradiated with 10.000 rads and stored at 10°C suffered a marked increase in the content of non-reducing sugar, a maximum value being reached 5 days after irradiation. The sugar content then fell and 26 days after irradiation it approximated to that of non-irradiated tubers. This temporary sweetening effect was independent of the date of irradiation. It was less, though still marked, if the irradiation dose was reduced to 3000 rads.