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The increasing demand for organic foods is explained mainly by consumers' concerns about the quality and safety of foods and their perception that organically produced foods are healthier and safer than conventional foods. Based on internationally available concentration data of organic and conventional vegetables (carrots, tomatoes, lettuce and spinach) and potatoes, the paper aims to investigate the scientific validity of nutrition claims as “no vegetable/potato has higher amounts of nutrient X than organic vegetables/potatoes” and “no vegetable/potato has lower amounts of contaminant Y than organic vegetables/potatoes”.

Detailed nutrient and contaminant databases were developed for organic and conventional vegetables separately. Non‐parametric (Mann‐Whitney test) methods were used to detect significant differences between both types of vegetables. A chi‐square test was used to compare the incidence of pesticide residues in organic and conventional vegetables.

From a nutritional and toxicological point of view, organic vegetables and potato in general are not significantly better than conventional vegetables and potatoes. For some nutrients and contaminants organic vegetables and potatoes score significantly better but for others they score significantly worse. Therefore, it becomes difficult to justify general claims indicating a surplus value of organic over conventional vegetables and potatoes. More data from controlled paired studies are needed to reconsider the use of claims for these organic plant foods in the future.

Only a limited number of studies comparing the nutrient and/or contaminant concentration of organic and conventional vegetables are available (“paired studies”). Additionally, the majority of the studies are of moderate or poor quality. The implication is that more of those paired studies are heavily needed. Another limitation of the study is the fact that most pesticide residue data originated from the USA, the EU and Australia.

So far only few studies compared both nutrient and contaminant contents between organic and conventional plant foods. This paper covers therefore an important, not well‐explored research sub area.

The purpose of this paper is to investigate the effect of partial substitution of wheat flour with sweet potato flour on the nutrient composition and sensory properties of bread.

Sweet potato flour was blended with wheat flour at 5, 10, 15, 20 and 25 percent levels of substitution for bread production. Proximate, minerals and antinutritional factors of the breads were investigated using AOAC methods. Sensory evaluation was carried out by a panel of 50 consumers. Data were subjected to analysis of variance and means were separated by Tukey’s comparison test at p <0.05. Results were reported as mean ± SD.

The nutritional and sensory quality of bread made from wheat flour supplemented with sweet potato flour at 5, 10, 15, 20 and 25 percent was investigated. Blending of sweet potato flour with wheat flour had significantly decreased the protein content (4.76–7.78 percent) while the ash (1.35–3.07 percent), crude fiber (0.24–1.03), carbohydrate contents (88.39–90.45 percent), iron, zinc, phosphorus and vitamin A contents were significantly increased ( p<0.05) with increasing sweet potato flour in the formulations. The tannin and phytate contents of the composite breads were low. Sensory evaluation of the breads revealed a mild reduction of the bread’s general acceptability with increase in the substitution level by sweet potato flour.

This study showed that the wheat flour used in making breads could be substituted with up to 15 percent sweet potato flour without compromising its nutritional quality, with only a mild reduction in sensory quality.

The purpose of this study was to compare the nutrient and antinutrient content of two improved sweet potato varieties released for drought prone areas of eastern Ethiopia.

Matured roots of two sweet potato varieties, namely, Berkume and Adu, were collected from Haramaya University, Toni Research Farm, Ethiopia. The sweet potatoes were ground into flour following standard procedure. Thereafter, proximate, dietary minerals and β-carotene were determined by official methods of analysis. The tannin and phytate contents were determined by colorimetric methods.

The moisture, protein, fat, fiber, ash, utilizable carbohydrate and gross energy varied from 6.23-6.61 per cent, 2.07-2.76 per cent, 1.25-1.52 per cent, 1.04-1.16 per cent, 3.38- 5.32 per cent, 90.03-91.45 per cent and 382.18-388.07 Kcal/100 g in both the sweet potato varieties. Potassium content (176.17 mg/100 g) was reported to be the highest and registered in Berkume variety, while the lowest mineral content (2.18 mg/100 g) determined was zinc in Adu sweet potato variety. The highest total carotenoid content (3.39mg/100 g) was recorded in Berkume sweet potato variety. The tannin and phytic acid contents ranged from 9.98 to 12.94 mg/100 g and from 0.24 to 0.31 mg/100 g in Berkume and Adu sweet potato varieties, respectively.

This study showed that the Berkume sweet potato variety has high nutritional potential and less antinutrient contents as compared with the nutritional value of many other roots and tuber crops documented in the FAO database and hence can contribute to reducing malnutrition in resource-poor settings of Ethiopia. Further work needs to be carried out on developing value-added products from Berkume sweet potato variety for its extensive utilization.

The North American fresh potato market has been in decline for over ten years, yet little consumer research has penetrated beyond the factors influencing the purchase decision. The purpose of this study is to provide a deeper understanding of the purchase decision for the fresh potato by exploring the linkages between the choice tactics employed in the store, post‐purchase evaluations in the home and the value orientations motivating consumption.

For this study, semi‐structured focus groups were conducted and analyzed using framework analysis.

This study presents a choice tactic formation and refinement model for the fresh potato that illustrates a feedback process between in‐home evaluations of the fresh potato and the four choice tactics employed at the point of purchase (potato size, color, shape and size uniformity). Each evaluative outcome related back to one of three value orientations (taste, health and lifestyle). Only two of the value orientations (taste and lifestyle) were found to be influencing the formation and refinement of these choice tactics. Positive and negative evaluative outcomes were also found to be dependent on whether participants thought of the potato as either fresh or prepared.

Detailed insights into a feedback process between in‐home evaluations of the fresh potato and the choice tactics employed at the point of purchase.

A better understanding of the determinants of demand through accurate estimates of the elasticity of import demand can help policymakers and exporters improve their market access and competitiveness. This study analyzed the EU's demand for imported potato from major suppliers between 1994 and 2018, with the aim to evaluate the competitiveness of Egyptian potato.

This study adopted an import-differentiated framework to investigate demand relationships among the major potato suppliers to the EU's. To evaluate the competitiveness of Egyptian potato on the EU market, expenditure and price demand elasticities for various suppliers were calculated and compared.

The empirical results indicated that as income allocation of fresh potatoes increases, the investigated EU markets import more potatoes from other suppliers compared to imports from Egypt. The results show that EU importers may switch to potato imports from other suppliers as the import price of Egyptian potatoes increases, which enter the EU markets before domestically produced potatoes are harvested.

Due to data unavailability, the present study relied on yearly data on quantities and prices of EU potato imports. A higher frequency of observations should allow for considering seasonal effects, and thereby providing a more transparent picture of market dynamics and demand behavior of EU countries with respect to potato import from various sources of origin.

The study used a system-wide and source differentiated approach to analyze import demand. In particular, the empirical approach allowed for comparing different demand models (AIDS, Rotterdam, NBR and CBS) to filter out the superior and most suitable model for that data because the suitability and performance of a demand model depends rather on data than on universal criteria.

Small farmers, being the primary producers of crops, are the key players in the food supply chain. Yet, they remain the most marginalized in the value chain. The marginalization of small farmers can affect food sustainability. The purpose of this paper is to identify opportunities for bringing more value to small farmers in an agricultural value chain.

This paper makes use of action research, studying the potato value chain, in a developing agricultural country Pakistan. The authors conducted an in-depth study of 37 farmers in four regions, each being a large potato growing ecosystem. The study examined the end-to-end decision-making processes, sources of input (both physical and information), cultivation and sales practices, cost structure, productivity and profitability of the farmers in potato farming.

Large variations exist in the crop yield, cost structure and profitability of farmers within each of and among the four regions due to differences in cultivation practices and approach to sales. There is a significant potential to lower costs, increase yield and enhance overall profitability by using the existing better processes. By addressing the issues faced by small farmers their profits can be potentially doubled. The paper also discusses potential means of recrafting and streamlining the value chain to bring more value to small farmers.

The paper provides a detailed account of how different interventions can increase the value for small farmers. Since the current food supply chain and sustainability are under stress, worldwide, the findings of this study have implications for farmers as well as policy makers.

The literature on streamlining the agricultural value chain and enhancing the share of small farmers is scarce. Improving the value chain and reducing the marginalization of small farmers is an essential step toward increasing food sustainability.

Rising energy expenditures due to more intensive use of energy in modern agriculture and increasing energy prices may affect rural households’ agricultural incomes, particularly the incomes of the rural poor in developing countries. However, the exact link between energy costs and income among the rural poor needs further empirical investigation. The purpose of this paper is to develop a deeper understanding of the relationship between energy use and family income, using household-level panel data collected from 500 potato farmers in a poor region of Northern China, where eliminating poverty by 2020 is now the top government priority.

The paper uses household survey data collected from six counties in a poor region in northern China in 2013 to measure the relationship between energy cost and family income. A fixed effect model is employed to estimate the relationship.

The findings indicate that potatoes play an important role in the surveyed families’ incomes, and that the energy costs of potato production have a significant negative relationship with family income. However, this negative relationship is only significant for farmers with low economic standing, such as those living below or just above the poverty line. The negative relationship between energy costs and family income is only significant for those cultivating a certain size of potato-sown area; it is insignificant for those cultivating smaller areas.

These findings indicate that, in general, reducing energy costs helps the poor increase their income but is not necessarily helpful to those with high economic standing or a relatively small potato-sown area. If rural development policies are to support poverty reduction and energy savings (at least in major potato production regions), interventions aimed at energy cost reduction may be effective only for the poor whose family income depends, to a relatively high degree, on potato production.

Using an analysis of marketing margins and the key dimensions of long‐term buyer‐seller relationships, it is possible to demonstrate that the supply chain for potatoes cultivated in the Red River Delta (Vietnam) is surprisingly efficient. While the prices paid to farmers are ultimately determined by supply and demand, the price farmers receive from traders and collector agents is influenced by tuber quality and the costs of transportation. Farmers are seldom dependent on their preferred trading partner and indicate that numerous alternative traders are available to purchase the potatoes they have harvested. While the traders similarly enjoy a strong positive relationship both with farmers and collector agents and their down‐stream customers, wholesalers report that they are much less satisfied in their exchange relationship with both the traders and the retailers. Wholesalers are more dependent on both their up‐stream and down‐stream trading partners and are more dissatisfied and less trusting of their exchange partners.

The purpose of this paper is to measure food loss and waste by material flow analysis (MFA) tool. Applying this methodology, the authors estimate wastage-related losses and discuss opportunities for more circular and sustainable practices in the Italian potato industry.

MFA is applied to two specific typologies as follows: ready-to-eat (chips) and dried potato products produced in Italy. The analysis refers to the year 2017 as the complete dataset useful for this study includes measurements until this year. A bottom-up and top-down mixed approach is applied, and functional unit refers to 1 t of potatoes consumed as final product.

MFA is applied to quantify and qualify material balance associated with 1 t of potatoes consumed as final product. In Italy, in 2017, more than 22,000 t of fresh tubers were lost, including 3,500–4,800 t of starch, equivalent to 52,800–72,600 GJs. Moreover, fewer than 23,000 t of skins and scraps were produced within industrial plants, not available for food but suitable for animal feed (dry skins are an excellent carbohydrates source in cattle and poultry feed), starch industry and bioenergy production (biogas and/or bioethanol).

This research is one of the few studies proposing MFA methodology as a tool to measure food waste. This analysis shows its utility in terms of food waste quality/quantity evaluation, supporting both company management and policymakers.

Clarify the effects of potato flour (PF) addition on dough properties and quality characteristics of pie bread, thus providing a theoretical basis for potato-wheat-yogurt pie bread processing.

The seven pie bread formulations were prepared with addition of different amount of PF (0, 10, 20, 30, 40, 50 and 60 per cent) by replacing wheat flour (WF). The influence of replacement of PF with WF on the dough development, gas behavior, microstructural, gluten-starch interaction inside dough matrix and the nutritional and textural properties of pie bread was analyzed.

Compared to dough with WF, dough height was decreased significantly but total gas volume showed no significant difference with the addition of PF (10-60 per cent), and the dough height was decreased gradually with the increasing addition of PF (p = 0.0012). Scanning electron microscopy and confocal laser scanning microscopy showed that dough with 10-30 per cent PF revealed smooth surface and continuous network structure was also existed between starch and gluten, this was similar to the structure of wheat dough, while the surface was rough and the connection was not continuous when the PF addition was further increased from 40 to 60 per cent. Nuclear magnetic resonance showed dough with 10-60 per cent PF presented larger content of immobilized water compared to the wheat dough, and its content was also increased with the increasing addition of PF (p = 0.0008). Pie bread with 10-60 per cent PF exhibited lower fat, carbohydrate content and energy value compared to the wheat pie bread, and the fat, carbohydrate, energy was further decreased with the increasing addition of PF (p = 0.0012, 0.0002, 0.0007, respectively), while the dietary fiber content increased (p = 0.0011). In addition, specific volume and height/diameter ratio showed no significant difference in pie bread with 0-40 per cent PF, which were 2.1-2.4 cm³/g and 0.16-0.19, respectively (p = 0.004), whereas they were reduced significantly when the PF was increased to 60 per cent (p = 0.001, p = 0.002). In addition, the lightness (L) of pie bread decreased gradually with the increasing amount of PF, and the browning index was increased. Pie bread with 0-40 per cent PF showed similar hardness, springness and chewiness value, which were also increased when the PF was increased to 60 per cent (p = 0.001). The above results indicated that PF could improve the nutritional quality of pie bread, and the appropriate addition amount should be no more than 40 per cent.

The mechanisms of this study should be clarified for further study.

PF was an excellent food ingredient and could be used for pie bread making at 30 per cent replacement level to overcome use of WF.

The results of this study can provide a new kind of potato staple food with high nutrition and low energy for market and consumers.

PF was first used to produce yogurt pie bread to improve the nutritional properties of traditional WF yogurt pie bread.