Ultrasonic methods are increasingly being used in the food industry for both food analysis and foodmodification. Ultrasound technology is relatively inexpensive, simple and cost-effective in terms ofenergy and time and is a non-destructive technique compared to other conventional technologies.The ultrasonic spectrum based on frequency and intensity is divided into two types, including lowfrequency (less than 100 kHz)-high-power (more than 1 W/cm2) ultrasound and high frequency(more than100 kHz) low-power (less than 1 W/cm2) ultrasound. The effect of ultrasound onvarious materials is caused by the formation, growth, and collapse of bubbles, which is referred toas cavitation. The ultrasonic spectrum based on frequency and intensity is divided into two types,including low frequency (less than 100 kHz)-high-power (more than 1 W/cm2) ultrasound and highfrequency (more than 100 kHz) low-power (less than 1 W/cm2) ultrasound. Ultrasound applicationsin the food industry are very diverse. This review summarizes the major popular applications of lowand high-power ultrasound in food science and technology.

Selenium is an essential trace element that is crucial for normal functioning of human body systemsand it is obtained from diet or dietary supplements. The concentration of selenium (Se) varies fromsoil-to-soil and therefore in various food types. We profiled the selenium concentration in the majorAfrican fresh foods and studied the effect of boiling, frying and overnight soaking on their seleniumcontent. The foods were taken to the chemistry laboratory, processed for determining seleniumconcentration in the fresh foods and then subjected to the various treatments before determiningtheir Se concentration using an atomic absorption spectrometer. Among the fresh foods studied,pumpkin seeds were found to have the highest Se concentration (109.25 ± 0.125 parts per billion(ppb)), while Irish potatoes had the lowest (16.25 ± 0.125 ppb). In most fresh foods studied, boilingand frying had the effect of reducing the Se concentration, except in yams that showed an increasedconcentration after frying. Overnight soaking of matooke (plantain bananas) and beans showed aneffect of causing a considerable reduction in the Se concentration from 36.375 ± 0.281 ppb and59.125 ± 0.031 ppb to 14.03 ± 0.441 ppb and 24.375 ± 0.281 ppb, respectively. Boiling and fryingcause a significant reduction in Se concentration of most African fresh foods. Overnight soaking ofmatooke and beans caused further reduction in the selenium concentration of the fresh foods. Thisimplies that people who pre-soak their food before cooking it are likely to lose more selenium thanthose who do not soak and may be more likely to suffer from Se deficiencies.

Lignocellulosic biomers have been found to possess great potential as substrates for variousbioconversion processes; this is due to their vast availability coupled with their renewable nature.The direct conversion of lignocellulosic substrates is however hindered by their rigid and complexstructural composition, which must be broken down via a process called pretreatment. This researchaimed at comparing the effects of different methods used in pretreating lignocellulose. Samples ofthe selected biomers were subjected to various methods of pretreatments (mechanical, chemical,physicochemical and a combination method). Compositional analysis of each biomer was carriedout before and after each pretreatment method, the pretreated biomers were then subjected tomicrobial hydrolysis using Trichoderma viride and Aspergillus niger for 5 days, after whichestimation of reducing sugar present was carried out. Analytical contents of the samples showedhigh cellulose, hemicellulose and lignin contents (36.39, 26.52, 13.62 and 43.30, 32.30, 6.42%respectively). The combination of 2 or more methods proved more efficient than other individualmethods, significantly increasing cellulose contents from 36.39% to 58.61% and 43.30% to 61.09%in wheat straw and corn stover respectively, while eliminating the lignin barrier from 13.62% to3.82% and 6.42% to 2.38% respectively. The reducing sugar results proved that Trichoderma viridehad the most sugar content of 0.55 g/g in corn stover after pretreatment with the combinationmethod, making it more effective in cellulose hydrolysis.

Food-borne diseases are caused by a wide range of microbiological and chemical or toxins withdifferent levels of severity, which range from mild sickness to life-threatening illness. The WorldHealth Organization estimates that the global burden of foodborne diseases is 420000 mortality andat least 1 in 10 people falls ill every year from eating contaminated food. African and South-EastAsia Regions have the highest burden of foodborne diseases. Several devastating outbreaks offoodborne diseases have been reported in Bhutan. This report presents the food safety surveillancedata for food samples collected between June 2019 to December 2021 from five Districts (Paro,Thimphu, Phuentsholing, Gelephu and Monggar). Ready-to-eat food samples were collected byFood inspectors and samples were shipped to Royal Centre for Disease Control (RCDC) maintaininga cold chain during transportation. The results show that 12.36% (n=78) of food samples were nonacceptabledue to indicator test organism contamination and 8.71% (n=55) of the RTE food sampleswere unacceptable due to the presence of the pathogenic organism. The common type of pathogenisolated was Staphylococcus aureus, and Bacillus cereus, and low detection of Aeromonas andShigella spp. The seasonality pattern of food contamination shows that most contamination occurredhigher during hot and wet seasons. The findings demonstrate that RTE is likely to cause foodborneillness. Therefore, education on personal hygiene, good manufacturing practices and food safetyaspect would improve food quality thereby reducing the incidence of foodborne incidences.

High intake of total fructose, total glucose and benzoic acid can cause many adverse health effects.Most commercially available fruit juice and nectar brands in Sri Lanka are not claimed on the labelabout the levels of fructose, glucose and benzoic acid in the products. Available brands of fruit juices[Mixed Fruit Juice (MFJ) and Mango Juice (MJ)] and fruit nectars [Mixed Fruit Nectar (MFN) andMango Nectar (MN)] were selected through a pre-validated questionnaire. Seven brands of MNand MFN were identified as mostly consumed and there was a significant difference (p<0.05) inthe total fructose and total glucose levels among the brands. Total fructose of MN and MFN was inthe range of 28.54 ± 3.03 gl-1 to 60.28 ± 5.04 gl-1 and 30.46 ± 8.56 gl-1 to 62.47 ± 9.27 gl-1respectively. Total glucose content of MN was in the range of 17.49 ± 5.39 gl-1 to 41.87 ± 2.11 gl-1and for MFN from 29.29 ± 4.34 gl-1 to 85.71 ± 5.64 gl-1. Total fructose in MJ and MFJ was in therange of 32.28 ± 0.86 gl-1 to 37.66 ± 0.55 gl-1 and 33.14 ± 0.87 gl-1 to 36.81 ± 1.81 gl-1 respectively.Three, out of the four brands of MN and MFN contained benzoic acid. One brand of MN and onebrand of MFN had exceeded the permitted level (120 mg/l) of benzoic acid. Benzoic acid waspresent in two, out of three brands of MJ and MFJ. It can be concluded that there is a variation intotal fructose, total glucose and benzoic acid contents in fruit nectars and juices available for sale inAnuradhapura town area. However, some brands have violated the Sri Lanka food regulations.

Coated skewers are very popular in Ouagadougou. This work aims to assess the microbial quality ofcoated skewers sold in the streets of Ouagadougou and their isolated Staphylococcus aureus andPseudomonas spp antimicrobial resistance. A total of 30 coated skewers samples were collectedfrom various processors for microbial analysis using standard methods. The antimicrobialresistance test was performed using the agar plate diffusion method. The microbial load variedfrom 6.0×104-1.7×108 cfu/g (aerobic mesophilic bacteria (AMB)), 1.5×10-2.7×107 cfu/g (coliform),0.0 to 6.1×101 (S. aureus) and 10-25 cfu/g (Pseudomonas spp.). Globally, 70% (21/30), 30%(09/30), 40% (12/30) and 6.67% (02/30) of the analyzed samples were unacceptable based on theload of AMB, coliform, S. aureus and Pseudomonas spp., respectively. Four coated skewers werecontaminated by Pseudomonas spp. About susceptibility to antimicrobial agents, 91.67% of S.aureus strains were resistant to ceftazidime and aztreonam, while a low resistance rate wasobserved for the other antibiotics. Pseudomonas spp strains, were resistant to cotrimoxazol (75%)but sensitive to the other antibiotics. These results highlight poor hygienic conditions of coatedskewers preparation in Ouagadougou. These practices contribute to their microbial contamination.Isolated bacteria showed a different level of resistance to the tested antibiotics. There is a need ofgood manufacturing practices to improve the hygienic quality of coated skewers.