The production of yam-derived (Dioscorea rotundata) foodstuffs is mainly performed by small and medium scale processors that employ old traditional methods. This can lead to differences in quality from processor to processor, and from location to location, with consequent safety concerns. As such, the effects of processing and post-processing phases (i.e., storage, transport, etc.) on the safety of some yam-derived foodstuffs—namely chips, flakes, and flour—has been evaluated, with a focus on bacterial and fungal contamination, aflatoxins, pesticides, and heavy metals (Pb, Ni, Cd and Hg). Yams harvested and processed in Nigeria were screened, being that the country is the largest producer of the tuber, with 70–75% of the world production. Results highlighted no presence of pesticides, however, many samples showed high levels of bacterial and fungal contamination, together with heavy metal concentrations above the recommended safety levels. No trend was observed between the items considered; it was noticed, however, that samples purchased from the markets showed higher contamination levels than those freshly produced, especially regarding bacterial and aflatoxins presence. The processing stage was identified as the most critical, especially drying. Nonetheless, post-processing steps such as storage and handling at the point of sale also contributed for chemical contamination, such as aflatoxin and heavy metals. The results suggested that both the processing and post-processing phases have an impact on the safety of yam chips, flakes, and flour.

Fresh yams are not shelf stable due to its high susceptibility to physiological deterioration; hence, its conversion into a more stable product like flour can stimulate its industrial application as a substitute to wheat flour. The influence of yam species, pretreatment, and drying method on the antinutritional factor and vitamin composition of high‐quality yam flour (HQYF) was determined. Four different yam species were pretreated with 0.28% potassium metabisulphite for 15 min and blanching at 70°C for 15 min. The differently pretreated slices were thereafter dried with cabinet dryer at 60°C for 48 h and open sun for 3 days, then milled into flour. The flour samples were analyzed for antinutritional and vitamin contents using standard laboratory procedures. The antinutritional factors in the high‐quality yam flour were significantly (p < .05) affected by yam specie, pretreatment, and drying methods. The low level of alkaloids (0.02 mg/100 g) and phytates (13.43 mg/100 g) in the flour samples from D. rotundata in this study underscores its safety for absorption in the body when consumed/used as food formulations. The main and interactive effect of specie of specie, pretreatment, and drying methods influenced the vitamin content of the high‐quality yam flour significantly (p < 0.05). The appreciable level of vitamin C (20.87–30.91 mg/100 g) recorded in all the HQYF could indicate the product of good nutritional quality for the consumers.

Protein dense, fiber-rich extruded snacks were produced from blend of bambara groundnut flour, cassava starch, and corn bran flour using a single screw cooking extruder. The snacks were analyzed for their physical properties and proximate composition using standard laboratory procedures. The expansion ratio, specific volume, breaking force, and breaking strength index (BSI) of the snacks ranged from 0.85 to 1.22, 0.75 to 1.30 g/cm³, 3.95 to 36.45 N, and 0.99 to 9.11 N/mm, respectively. The breaking force and BSI were high and increased at increasing levels of cassava starch and corn bran inclusion. Moisture, protein, fat, carbohydrates, crude fiber, and total dietary fiber contents of the snacks were 5.40–10.80, 3.26–17.62, 0.68–10.35%, 60.56–85.03, 0.32–4.78, and 7.36–28.74%, respectively. The study revealed a great potential of obtaining a nutrient dense extruded snack from underutilized plant commodity (bambara groundnut) and waste from corn milling (corn bran). Findings from this study will find numerous applications in gluten-free products. It is also capable of enhancing the productivity and utilization of bambara groundnut (an underutilized nutritious legume). The study also attempted to add value to waste product of corn milling (corn bran).

This study aimed at producing gluten-free chicken sausages using High-Quality Cassava Flour (HQCF) and coconut composite flour as fillers. The composite flour constituted 20% of the sausage recipe. D-optimal mixture design was used to optimize the inclusion of the two flours(HQCF (12.5–17.25%) and coconut flour (2.5 − 7.5%)) in the chicken sausages. The proximate composition, textural and physicochemical properties of the sausages were determined. Fiber content was highest in the sample having the higher inclusion amount of both flours. An optimized inclusion level of 15.20% HQCF and 4.80% coconut flour was selected as the best. Sensory acceptability of the optimized sausage revealed that there was no significant (p > .05) difference in the aroma, appearance, taste and tenderness compared to sausage processed from wheat flour and HQCF separately. The study concluded that coconut flour (4.80%) and HQCF (15.20%) can replace wheat flour as fillers in chicken sausages.

Postharvest physiological deterioration (PPD) of fresh cassava roots limits their shelf-life to about 48 h. There is a demand for simple, cheap, and logistically feasible solutions for extending the shelf life of fresh cassava roots in industrial processes. In this study, three different types of bag materials were tested, namely woven polypropylene, tarpaulin, and jute as a potential storage solution for cassava roots with different levels of mechanical damage. Microclimate related to temperature, humidity, and carbon di-oxide (CO₂) was monitored in order to understand the storage conditions for up to 12 days. The results showed that fresh cassava roots could be stored for 8 days, with minimal PPD and starch loss (2.4%). However, roots with significant mechanical damage in the form of cuts and breakages had a considerably shorter shelf life in the storage bag, compared to whole roots and roots with retained stalk (peduncle) where roots are connected to the main plant. Wetting of the roots and bag material were not significant factors in determining the shelf life and starch loss. Carbon dioxide concentration in the stores was significantly correlated with the starch loss in fresh cassava roots and is proposed as a possible method for continuously and remotely monitoring starch loss in large-scale commercial operations and reducing postharvest losses.

Snack industry is recently focused on the production of snacks with minimal oil content and enhanced quality attributes which prompted the need to study the changes in snack matrices produced from cassava starch processed from three varieties of cassava roots (TMS‐950289, TME‐419, and TMS‐30572) and soy protein isolate blends fried in soybean oil. Effect of frying temperature (170–180°C), frying time (2–4 min), soy protein isolate inclusion level (5%–15%) on proximate composition, color changes, expansion, texture, and sensory attributes of the snacks was investigated. Optimization of process variables was carried out based on a factorial design (2 level by 3 factor) in the Design Expert version 6.0.8, and models were generated showing the relationship between the independent variables and the responses. The desired goal for each constraint (processing conditions) was kept within 170–180°C for 2–4 min, while all responses, except chewiness, expansion, yellowness, and protein, were set at minimum. Evaluation of sensory attributes of the optimized sample was carried out to determine its level of desirability. The optimized frying conditions for matrices produced from starches of TMS‐950289 are 170°C/4 min/5% SPI with desirability value of 0.507; from TME‐419 are 180°C/2 min/5% SPI with desirability value of 0.475 while for those from TMS‐30572 are 170°C/4 min/15% SPI with desirability value of 0.459. At higher SPI level, the protein content was high at 170°C. At 4 min frying time for all the varieties, the moisture content reduces. The most desired optimized fried snack produced from starch of TMS‐30572 (containing 15% SPI) had higher crispness and lower oil content than other optimized fried snacks.