Multimode ultrasonic-assisted decontamination of fruits and vegetables: A review.

Fruits and vegetables (F&V) are a significant part of our diet consumption. Microbial and pesticide residues are the predominant safety hazards of F&V consumption. Ordinary water washing has a very limited effect on removing microorganisms and pesticide residues and requires high water usage. Ultrasound, as an environmentally friendly technology, shows excellent potential for reducing microbial contamination and pesticide residue. This paper summarizes the research on ultrasound application in F&V washing, including the removal of microbial and pesticide residues and the comprehensive effect on their physicochemical characteristics. Furthermore, multimode ultrasonic-assisted techniques like multi-frequency and sequential ultrasound, combined with novel and conventional methods, can enhance the ultrasound-based effect and be more effective and sustainable in preventing F&V from microbial contamination. Overall, this work explicitly establishes the background on the potential for ultrasound cleaning and disinfection in the food industry as a green, effective, and ultimate method of preventing foodborne illnesses.

Date fruit melanin is primarily based on (-)-epicatechin proanthocyanidin oligomers.

Plant-based melanin seems to be abundant, but it did not receive scientific attention despite its importance in plant biology and medicinal applications, e.g. photoprotection, radical scavenging, antimicrobial properties, etc. Date fruit melanin (DM) has complex, graphene-like, polymeric structure that needs characterization to understand its molecular properties and potential applications. This study provides the first investigation of the possible molecular composition of DM. High performance size-exclusion chromatography (HPSEC) suggested that DM contains oligomeric structures (569-3236 Da) and transmission electron microscopy (TEM) showed agglomeration of these structures in granules of low total porosity (10-1000 Å). Nuclear magnetic resonance (NMR) spectroscopy provided evidence for the presence of oligomeric proanthocyanidins and electron paramagnetic resonance (EPR) spectroscopy revealed a g-factor in the range 2.0034-2.005. Density functional theory (DFT) calculations suggested that the EPR signals can be associated with oligomeric proanthocyanidin structures having 4 and above molecular units of (-)-epicatechin. The discovery of edible melanin in date fruits and its characterization are expected to open a new area of research on its significance to nutritional and sensory characteristics of plant-based foods.

Production, acceptability, nutritional and pasting properties of orange-flesh sweet potato, cowpea and banana flour mix.

Promoting the intake of foods rich in vitamin A is key to combating the increase in vitamin A deficiency. This research focused on the utilization of orange-fleshed sweet potatoes (a tuber-based food), cowpea (a pulse), and ripe bananas (a fruit) for the production of flour mix as a means to reduce Vitamin A deficiency in children. Different ratios of sweet potato-cowpea-banana (PCB) mix, resulting in 8 different blended samples, were optimized. The flour mix was evaluated for its overall acceptability, vitamin A content, beta-carotene, and other nutritional and functional properties. The panelists rated the sweet potato-cowpea banana blends labeled PCB8 (60% OFSP, 30% cowpea, 5% ripe banana flour, and 5% sugar) as most preferred and acceptable with average scores of 8.96 points for color, 8.75 points for flavor, 8.88 points for appearance, 8.33 points for taste, 8.07 points for texture, and 8.39 points for overall acceptability on a 9-point hedonic scale. The vitamin A and beta-carotene contents ranged 7.62 to 8.35 mg/100 g and 0.15-0.17 mg/100 g for all blends. A significant difference in the functional properties of the flour mix were observed with an increase in the ratio of sweet potato flour addition. Findings from this study show that the flour mix PCB4 (65% sweet potato, 30% cowpea, and 5% ripe banana flour) was acceptable (8.15) and is recommended based on its vitamin A content (8.35 mg/100 g), nutritional properties, and functional properties. The study showed that locally available food commodities have good nutritional value that will help reduce vitamin A deficiency in children.

Heat source replacement strategy using catalytic infrared: A future for energy saving drying of fruits and vegetables.

Drying is an important process for fruits and vegetables, which requires a lot of heat and the heat sources are mainly coal, electricity, natural gas, and solar energy. Most of the heat is usually wasted due to the long drying process and poor transfer efficiency. The use of coal also pollutes the environment. The national electricity curtailment policy regulates the drying industry. Therefore, the fruits and vegetables drying industry is facing new challenges due to its own development needs and external factors. Catalytic infrared drying (CIR) technology brings solutions to these problems. Compared with other drying technologies, CIR has a high drying efficiency and can effectively reduce the use of electric energy, avoid waste, and minimize pollution of water. However, improper processing conditions still cause quality deficits such as severe browning, and the drying is difficult due to weak infrared penetration. Although CIR has shortcomings, it is still expected to establish an energy-saving and efficient fruit and vegetable drying system.

Application and Acceptability of Microbiomes in the Production Process of Nigerian Indigenous Foods: Drive towards Responsible Production and Consumption.

In Nigeria, the use of microorganisms for food product modulation, development, and commercialization through biotechnological innovations remains unexplored and unaccepted. The microbiome-based sustainable innovation in the production process of Nigerian indigenous food requires a vigorous drive toward responsible consumption and production. The production process of locally fermented beverages and foods culturally varies in terms of fermentation techniques and is characterized by the distinctiveness of the microbiomes used for food and beverage production. This review was conducted to present the use of microbiome, its benefits, and utility as well as the perspectives toward and mediatory roles of biotechnology on the processing of locally fermented foods and their production in Nigeria. With the current concerns on global food insecurity, the utilization of modern molecular and genetic sciences to improve various rural food processing technologies to acceptable foreign exchange and socioeconomic scales has been gaining attention. Thus, further research on the various types of processing techniques for locally fermented foods using microbiomes in Nigeria is needed, with a focus on yield optimization using advanced techniques. This study demonstrates the adaptability of processed foods locally produced in Nigeria for the beneficial control of microbial dynamics, optimal nutrition, therapeutic, and organoleptic characteristics.

Application of ultrasound and its real-time monitoring of the acoustic field during processing of tofu: Parameter optimization, protein modification, and potential mechanism.

Tofu is nutritious, easy to make, and popular among consumers. At present, traditional tofu production has gradually become perfect, but there are still shortcomings, such as long soaking time, serious waste of water resources, and the inability to realize orders for production at any time. Moreover, tofu production standards have not yet been clearly defined, with large differences in quality between them, which is not conducive to industrialized and large-scale production. Ultrasound has become a promising green processing technology with advantages, such as high extraction rate, short processing time, and ease of operation. This review focused on the challenges associated with traditional tofu production during soaking, grinding, and boiling soybeans. Moreover, the advantages of ultrasonic processing over traditional processing like increasing nutrient content, improving gel properties, and inhibiting the activity of microorganisms were explained. Furthermore, the quantification of acoustic fields by real-time monitoring technology was introduced to construct the theoretical correlation between ultrasonic treatments and tofu processing. It was concluded that ultrasonic treatment improved the functional properties of soybean protein, such as solubility, emulsifying properties, foamability, rheological properties, gel strength, and thermal stability. Therefore, the application of ultrasonic technology to traditional tofu processing to optimize industrial parameters is promising.

Fermented Gluten-Free Multi-Grain Cereal Paste Development: The Role of the Orange-Fleshed Sweet Potato (OFSP) as a Dietary Supplement.

Vitamin A deficiencies is a becoming persistent among young children and a growing concern to parents in sub-Saharan Africa, especially in crisis-affected areas. Fermented cereal paste from maize, millets, and sorghum grains are significant food for young children. Thus, the study focuses on food fortification using orange-fleshed sweet potato (OFSP) as fortifier as studies have confirmed the presence of nutrients that can help meet the Vitamin A dietary requirement. The cereals were soaked ambient temperature (27 ± 1°C) for 72 hours and were blended with OFSP (90:10, 80:20, 70:30, 60:40, 50:50), and the formulated products were studied for Vitamin A, ß-carotene, proximate composition, physicochemical, functional properties, and storage. Application of OFSP as forticant increased the Vitamin A (4.98-6.65 mg/100 g), ß-carotene (0.10-0.17 mg/100 g) and the calorific value (222.03-301.75 kcal) of the gluten-free multi-grain cereal paste. The addition of OFSP also increased the ash content (1.41%-3.35%), crude fiber (2.56%-4.225%), carbohydrate (39.83%-48.35%), total solid content (55.20%-60.87%), and water absorption capacity (112.20%-137.49%) of the formulated cereal samples. The fortified fermented paste was objectively stable throughout on the shelf from the storage studies. The study deduced that addition of orange-fleshed sweet potato to fermented mixed cereal paste as a fortifier can help increase the nutritional quality of the complementary food.

Natural and low-caloric rebaudioside A as a substitute for dietary sugars: A comprehensive review.

For health and safety concerns, traditional high-calorie sweeteners and artificial sweeteners are gradually replaced in food industries by natural and low-calorie sweeteners. As a natural and high-quality sugar substitute, steviol glycosides (SvGls) are continually scrutinized regarding their safety and application. Recently, the cultivation of organic stevia has been increasing in many parts of Europe and Asia, and it is obvious that there is a vast market for sugar substitutes in the future. Rebaudioside A, the main component of SvGls, is gradually accepted by consumers due to its safe, zero calories, clear, and sweet taste with no significant undesirable characteristics. Hence, it can be used in various foods or dietary supplements as a sweetener. In addition, rebaudioside A has been demonstrated to have many physiological functions, such as antihypertension, anti-diabetes, and anticaries. But so far, there are few comprehensive reviews of rebaudioside A. In this review article, we discuss the physicochemical properties, metabolic process, safety, regulatory, health benefits, and biosynthetic pathway of rebaudioside A and summarize the modification methods and state-of-the-art production and purification techniques of rebaudioside A. Furthermore, the current problems hindering the future production and application of rebaudioside A are analyzed, and suggestions are provided.

Effects of cutting and drying method (vacuum freezing, catalytic infrared, and hot air drying) on rehydration kinetics and physicochemical characteristics of ginger (Zingiber officinale Roscoe).

The purpose of this study was to discuss the effects of cutting methods (transverse cutting [TC] and longitudinal cutting [LC]) and drying methods (vacuum freeze-drying [FD], hot air drying [HD], catalytic infrared drying [CID]) on rehydration kinetics and physical and chemical characteristics of rehydrated ginger. The research results showed that the rehydration rate and equilibrium moisture content increased with an increase in temperature. LC samples had a higher rehydration rate, while TC samples showed higher equilibrium moisture. Peleg model can fit the rehydration curve of the sample well. The highest coefficient of determination (R2 ) was 0.99, while the sum of squares error and lowest chi-square (χ2 ) was close to zero. Compared with fresh samples, the rehydrated ginger slices had lower gingerol content, total phenol content (TPC), total flavonoid content (TFC), and higher antioxidant activity. The different cutting methods had no significant effect on the physical and chemical properties of rehydrated ginger. In conclusion, TC-CID rehydrated products have better retention of gingerol, TPC, TFC, and antioxidant properties, which was similar to the principal component analysis. PRACTICAL APPLICATION: The results of this study show that transverse cutting combined with catalytic infrared drying is a unique processing technology. Due to the short xylem of transverse cutting ginger, the xylem diameter can be restored during rehydration, the balanced water content was high, and the quality of dried ginger can be restored to the greatest extent. This makes food processors competitive in the operation process and provides better services to consumers.

Comparison of ultrasound and ethanol pretreatments before catalytic infrared drying on physicochemical properties, drying, and contamination of Chinese ginger (Zingiber officinale Roscoe).

This study aimed to investigate the effects of different pretreatment methods on the drying process and quality of catalytic infrared dried ginger slices, particularly the safety quality. Four different pretreatments strategies were used: sample submerged in distilled water, water + US pretreatment, ethanol pretreatment, and ethanol + US pretreatment. The results showed that all pretreatments reduced drying time, and sample pretreatment by ethanol + US had the highest drying efficiency, hardness, highest total phenolic content, and total flavonoid content retention. However, these pretreatments slightly decreased the rehydration ratio and gingerol content. The possible explanation for these results has been put forward by microstructure analysis. CIR-dried ginger samples were pretreated by four methods required by the agricultural standards of China. This study provides a new perspective on the commercial application of ethanol + US pretreatment for CIR-dried ginger slices.

Production of a Complementary Food: Influence of Cowpea Soaking Time on the Nutritional, Antinutritional, and Antioxidant Properties of the Cassava-Cowpea-Orange-Fleshed Potato Blends.

Soaking and incorporation of legumes for fortification are essential to a complementary food production process. Cassava, orange-fleshed potato, and cowpeas are sustainably cheap, locally available, and underutilized for food biofortification. This study investigated the effect of cowpea soaking time (3, 6, and 9 h) on different composition ratios of cassava, cowpea, and orange-fleshed sweet potato (CCP) blends (50 : 40 : 10 (EC), 50 : 30 : 20 (FC), 50 : 20 : 30 (GC), and 50 : 50 : 0 (HC)). Each blend was assayed for pH, antinutrient, antioxidant, and proximate contents. Results obtained showed that the CCP blends were significantly influenced by the length of cowpea soaking. Moisture and fiber content decreased significantly (P ≤ 0.05) with increased steeping time (3 to 9 h) for the cassava-cowpea-OFSP blends. The blends were significantly different (P ≤ 0.05) in terms of their protein, fiber, fat, ash, and carbohydrate contents. The moisture content of the EC blend was significantly different from only FC and HC blends, respectively. Six (6) hours of soaking showed no significant difference in the nutritional composition of the flour samples compared with 9 hours. The soaking length optimizes the health and nutrient-promoting factors in the various blend samples while also reaffirming cowpeas as a viable biofortification option for use in complementary food production.

Optimum Boiling Duration and Its Effect on Nutritional Quality and Acceptability of Mechanically Dehulled Unfermented Locust Bean Seeds.

Most locust bean processing is still carried out locally in Africa. Dehulling is one of the major challenges encountered in traditional processing of locust bean seeds. Boiling time prior to dehulling is vital for nutritional status of locust bean. Hence, this study explored the influence of boiling duration before dehulling on the nutritional quality of mechanically dehulled locust bean seeds. The samples were subjected to four different boiling durations (1∼4 h) and the resulting effects on the overall acceptability, proximate composition, mineral content, and pH were evaluated. Locust beans boiled for 2 h and dehulled at the speed of 398 rpm gave the highest crude protein content, crude fiber, crude fat, and ash content. The pH ranged from 5.48 to 5.77, while boiling improved the mineral content ranging from 0.25∼0.48 mg/100 g (potassium), 16.80∼28.00 mg/100 g (calcium), 3.85∼6.73 mg/100 g (sodium), and 40.00∼52.40 mg/100 g (magnesium). The tedious labour during dehulling of locust bean seeds can be reduced at 398 rpm dehulling speed without adversely affecting the slightly acidic status and nutritional quality; thus enhancing quality and overall acceptability. Adoption of boiling raw locust bean seeds for 2 h under pressure prior to dehulling is a valuable procedure to eliminate long hours of boiling and tedious labour during local and industrial production.

Performance evaluation and optimization of a Moringa Oleifera depodding machine: A response surface approach.

Depodding of moringa which is still being carried out manually by removing with hand or by hitting a bag containing the pods is time-consuming, labour intensive and not economical. The demand for quality oil-bearing moringa seeds that have a wide area of industrial applications necessitates innovative deppoding techniques that will improve its market value. To ameliorate these problems, moringa depoddding machine has been developed but studies on performance evaluation and optimal parameter setting are sparsely reported. This study therefore, evaluated the effects of the processing factors (moisture content (MC) and speed of rotation (SR)) levels on the performance (throughput capacity (TP), effective throughput capacity (ETP), labour requirement (LR), depodding coefficient (DC), coefficient of wholeness (CW), depodding efficiency (DE), depodded kernel (DK), undepodded kernel (UK), small broken kernel (SBK), and big broken kernel (BBK)) of the designed and fabricated moringa depodding machine using the response surface methodology and test between subjects-effects. The experimental design used was a two factor, three levels i-optimal randomized design. Mathematical models relating the process factors to performance were developed. The predicted optimum results obtained were validated using the observed values of the experiment. MC and SR were found to have a significant effect on the performance of the machine. The predicted optimum performance of the machine were 113.73 kg/hr, 109.45 kg/hr, 0.85 man-hour required/Kg, 96.15 %, 0.96, 93.93 %, 0.98, 0.02, 10.64 %, and 1.24 % for TP, ETP, LR, DC, CW, DE, DK, UK, SBK, and BBK respectively at MC and SR of 10.10 % wet basis and 564 rpm. The experimental values at these processing conditions were close to the predicted optimum results obtained with little deviations which were statistically insignificant. The selected models sufficiently predicted the performance of the developed machine.