Safety of Yam-Derived (Dioscorea rotundata) Foodstuffs-Chips, Flakes and Flour: Effect of Processing and Post-Processing Conditions

Physicochemical Properties of Sago- and Corn Flour-Based Rice Analogues Fortified with Black-Eyed Bean Flour and Skimmed Milk Powder

Research background

With the increasing consumption of food commodities, particularly rice, and the substantial volume of food imports in Indonesia, there is an increasing need to explore alternative food sources. Rice analogues emerge as a potential substitute for traditional rice, serving as a viable staple food option. The aim of this study is to investigate the effect of the composition of raw material, namely sago and corn flour, on the physicochemical properties and consumer acceptance of rice analogues.

Experimental approach

The rice analogues were produced using the hot extrusion method. The nutritional content (protein, carbohydrate, fat, moisture, fibre and ash) of the product was then analysed. Thermal stability and morphological properties were determined using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. A consumer acceptance test including taste, texture, aroma and colour was also carried out to evaluate the quality of cooked rice analogues.

Results and conclusion

The results showed that the rice analogue produced by hot extrusion at 70 °C with black-eyed beans (15 % m/m) and skimmed milk powder (0.5 % m/m) had the most significant nutritional improvements such as increased content of protein, fat, carbohydrate, moisture content, ash and fibre. However, it should be noted that increasing the extrusion temperature above 70 °C meant that both density and hardness could no longer be controlled due to gelatinisation. Furthermore, 30 participants in the consumer acceptance test rated the texture, aroma, taste and colour positively, underlining the potential of rice analogue as a nutritious and attractive alternative to natural rice. The rice analogue made from modified sago with additional ingredients of corn and black-eyed beans has similar properties to natural rice.

Novelty and scientific contribution

The combination of sago, corn and black-eyed bean flour as the main ingredients of the rice analogue is a novelty of this study. Furthermore, its nutritional profile exceeds that of natural rice, making it a viable and acceptable alternative in times of rice scarcity.

Evaluation of selected minerals and health risk and proximate analysis of wasawasa (a street food)

This study was carried out to determine the proximate composition and the potential heavy metal health risk that may be associated with the consumption of wasawasa, a dish made from locally milled yam peels, by examining the presence of six metals (iron, nickel, chromium, sodium, and magnesium and potassium) in samples procured. Sixteen (16) samples of ready-to-eat wasawasa were collected from Aboabo, Manhyia, Sawaba, Asawase, Adenyase, and Ayigya in Kumasi, since these are the communities where wasawasa is mainly produced, sold, and consumed. The samples were digested with a nitric, perchloric, and sulfuric acid mixture and analyzed using a microwave plasma atomic emission spectrometer (Agilent 4210 MP-AES). The average concentrations of metals were Na (8506.88 mg/kg), Mg (222.63 mg/kg), Fe (84.45 mg/kg), Cr (2.31 mg/kg), K (1702.08 mg/kg, and Ni (1.12 mg/kg). Proximate analysis was used to determine Protein, fat, ash, moisture, and fiber content of the local wasawasa, which were found to be 15.667 %, 0.45 %, 1.00 %, 27.54 %, and 0.41 %, respectively. The hazard index of the heavy metals (Fe, Ni and Cr) for both adults and children were each greater than one, indicating the population is likely to experience non-carcinogenic effects from the consumption of wasawasa.

A review on microorganisms and mycotoxin contamination of selected 'swallow meals' - Potential health risks to consumers

Swallow is a local parlance used by Nigerians to describe ready-to-eat pasty foods rich in carbohydrates which include fufu, pounded yam, amala, eba, lafun, tuwo, among others; molded in small size balls using the palm and dipped inside a bowl of nutritious and delicious soup (okro, edikaikong, egusi, bitter leaf soups etc.) before swallowing it. Swallow meals are often prepared in households and eateries, without strict implementation of food hygiene, which predisposes the meal to contamination by microorganisms. The use of palm, often not properly washed, to eat swallow meal is a common practice that is capable of contaminating the food. Since swallow meals are regarded as street foods, microbial contamination, and subsequent release of mycotoxins above permissible limits into the food is a threat to public health. Therefore, we reviewed scientific papers published from 2000 to 2023 that reported various microorganisms and mycotoxins associated with swallow meals, starting from the preparation stages to the plate-ready meal. The dominant bacteria reported were Bacillus spp. and Staphylococcus spp., while the fungi are Aspergillus spp. Mycotoxins, which include aflatoxin, fumonisins, among others, were detected in some swallow meals, soup ingredients, and raw foodstuffs. Although only two incidences of foodborne outbreaks linked to contaminated swallow meals were reported, there is a need to regularly monitor the microbiological quality of the meals to avoid future outbreaks.

Variations of the fungal microbiome in Corydalis Rhizoma with different collection areas, processing methods, and storage conditions

Corydalis Rhizoma (CR, Yanhusuo in Chinese) has been widely used as an analgesic in herbal medicine and functional food. Cases of fungal and mycotoxin contamination in CR have been reported. In this study, the composition and diversity of fungal microbiome in CR samples from four herbal markets and two processing methods were investigated by DNA metabarcoding. Variations of the fungal microbiome in CR during cold and conventional storage were monitored. Results showed that Aspergillus was the dominant genus and saprotroph was the dominant trophic mode. Six potential toxigenic fungi, namely, Aspergillus fumigatus, Aspergillus ostianus, Aspergillus terreus, Penicillium citrinum, Penicillium oxalicum, and Trichothecium roseum, were detected. Differences in fungal composition and diversity among various groups based on collection areas and processing methods were also observed. Moreover, the relative abundance of dominant genera in CR samples stored at different temperatures was significantly different and changed with storage time. This study is the first to reveal the influence of collection areas, processing methods, and storage conditions on the fungal microbiome in CR, which was expected to provide a basis for control strategies of fungal contamination in the industrial chain of CR.

Fungal composition, quantification of mycotoxins, and enzyme activity in processed Solanum tuberosum Linn (potato) products stored at different relative humidity

AIM

Postharvest loss of potatoes at the peak of harvest is of global concern. This study aimed to determine the quality of stored processed potato products based on fungal composition, mycotoxin contamination, and fungal enzyme activity.

MATERIALS AND METHODS

Potato products from three cultivars (Caruso, Marabel, and Nicola) were grouped as peeled or unpeeled, oven- or sun-dried, and all samples were in flour form. Samples were incubated separately for 6 weeks at 25%, 74%, and 87% relative humidities (RH) at 25°C. The pH, moisture content (MC), visible deterioration, mycotoxin, fungal identity by DNA sequencing, and enzyme activity were determined.

RESULTS

Results of grouped products (based on variety, drying, and peeling method) revealed that MC increased in the oven-dried samples and the pH value reduced after incubation. About 26% of the products at 87% RH showed visible deterioration, low amounts of fumonisin were detected in fermented potato product and nine fungal genera were identified across the three RH levels. Enzyme activities by Aspergillus niger, Fusarium circinatum, and Rhizopus stolonifer isolates were confirmed.

CONCLUSION

RH influenced deterioration and fungal activities in some stored processed potato products. Low levels of fumonisin were detected.

Illumina-Based Analysis Yields New Insights Into the Fungal Contamination Associated With the Processed Products of Crataegi Fructus

Crataegi Fructus, a medicinal and edible herb in China, has been considered a popular dietary supplement globally. It is used for the treatment of dyspepsia and chronic heart failure according to the Chinese Pharmacopoeia (2020). However, fungal contamination in Crataegi Fructus affects its quality and safety, thus preventing its global promotion. In this study, we comprehensively studied the fungal community in processed products of Crataegi Fructus by high-throughput sequencing. A total of 21 Crataegi Fructus samples were collected from five provinces in China, and the samples were divided into five groups based on collection areas, as well as into three groups based on processing methods. We then targeted the internal transcribed spacer 2 sequence through the Illumina Miseq PE300 platform to investigate fungal composition and diversity. Results showed that all 21 samples were detected with fungal contamination, and Ascomycota was dominant at the phylum level. In the groups based on collection areas, Dothideomycetes, Pleosporaceae, and Alternaria were dominant at the class, family, and genus levels, respectively. In the groups based on processing methods, Dothideomycetes, Aspergillaceae, and Alternaria were the most abundant at the class, family, and genus levels, respectively. Differences in fungal communities between various groups were also observed. Furthermore, a total of 115 species were identified, among which seven were potential toxigenic, namely, Trichothecium roseum, Alternaria tenuissima, Aspergillus carbonarius, Penicillium brevicompactum, Aspergillus fumigatus, Rhizopus microspores, and Pichia fermentans. In conclusion, this study reveals great fungal richness and diversity of Crataegi Fructus, providing references for the prevention and control of fungal contamination of Crataegi Fructus in practical production.

The Potential of Selected Agri-Food Loss and Waste to Contribute to a Circular Economy: Applications in the Food, Cosmetic and Pharmaceutical Industries

The food sector includes several large industries such as canned food, pasta, flour, frozen products, and beverages. Those industries transform agricultural raw materials into added-value products. The fruit and vegetable industry is the largest and fastest-growing segment of the world agricultural production market, which commercialize various products such as juices, jams, and dehydrated products, followed by the cereal industry products such as chocolate, beer, and vegetable oils are produced. Similarly, the root and tuber industry produces flours and starches essential for the daily diet due to their high carbohydrate content. However, the processing of these foods generates a large amount of waste several times improperly disposed of in landfills. Due to the increase in the world’s population, the indiscriminate use of natural resources generates waste and food supply limitations due to the scarcity of resources, increasing hunger worldwide. The circular economy offers various tools for raising awareness for the recovery of waste, one of the best alternatives to mitigate the excessive consumption of raw materials and reduce waste. The loss and waste of food as a raw material offers bioactive compounds, enzymes, and nutrients that add value to the food cosmetic and pharmaceutical industries. This paper systematically reviewed literature with different food loss and waste by-products as animal feed, cosmetic, and pharmaceutical products that strongly contribute to the paradigm shift to a circular economy. Additionally, this review compiles studies related to the integral recovery of by-products from the processing of fruits, vegetables, tubers, cereals, and legumes from the food industry, with the potential in SARS-CoV-2 disease and bacterial diseases treatment.

Assessment of the vigor of rice seeds by near-infrared hyperspectral imaging combined with transfer learning

Rice seed vigor plays a significant role in determining the quality and quantity of rice production. Thus, the quick and non-destructive identification of seed vigor is not only beneficial to fully obtain the state of rice seeds but also the intelligent development of agriculture by instant monitoring. Thus, herein, near-infrared hyperspectral imaging technology, as an information acquisition tool, was introduced combined with a deep learning algorithm to identify the rice seed vigor. Both the spectral images and average spectra of the rice seeds were sent to discriminant models including deep learning models and traditional machine learning models, and the highest accuracy of vigor identification reached 99.5018% using the self-built model. The parameters of the established deep learning models were frozen to be feature extractor for transfer learning. The identification results whose highest number also reached almost 98% indicated the possibility of applying transfer learning to improve the universality of the models. Moreover, by visualizing the output of convolutional layers, the progress and mechanism of spectral image feature extraction in the established deep learning model was explored. Overall, the self-built deep learning models combined with near-infrared hyperspectral images in the determination of rice seed vigor have potential to efficiently perform this task.

Sentinel species for biomonitoring and biosurveillance of environmental heavy metals in Nigeria

Nigeria receives copious annual precipitation to nourish its forests and agriculture, it has an extensive river drainage system, and it possesses valuable mineral deposits that stimulate both commercial and artisan mining activities. The combination of these features complicates Nigeria's efforts to produce adequate amounts of healthy foods to support its population. Toxic heavy metals like lead, cadmium, and mercury, and toxic metalloids such as arsenic, are also present in its mineral deposits and they migrate gradually into the soil and water of Nigeria by natural means. However, mining activities can liberate higher levels of toxic metals, which adversely affect Nigerian ecosystems and its food chains. Thus, environmental pollution due to anthropogenic activities is a major public health concern in Nigeria. This review covers the importance of native Nigerian and African wild and cultivated plants along with livestock and wild animals as sentinel species to evaluate heavy metals as environmental stressors and the use of sentinel species for food safety monitoring and for predicting potential risks to human health.