The distribution, fate, and environmental impacts of food additive nanomaterials in soil and aquatic ecosystems

Nanomaterials in the food industry are used as food additives, and the main function of these food additives is to improve food qualities including texture, flavor, color, consistency, preservation, and nutrient bioavailability. This review aims to provide an overview of the distribution, fate, and environmental and health impacts of food additive nanomaterials in soil and aquatic ecosystems. Some of the major nanomaterials in food additives include titanium dioxide, silver, gold, silicon dioxide, iron oxide, and zinc oxide. Ingestion of food products containing food additive nanomaterials via dietary intake is considered to be one of the major pathways of human exposure to nanomaterials. Food additive nanomaterials reach the terrestrial and aquatic environments directly through the disposal of food wastes in landfills and the application of food waste-derived soil amendments. A significant amount of ingested food additive nanomaterials (> 90 %) is excreted, and these nanomaterials are not efficiently removed in the wastewater system, thereby reaching the environment indirectly through the disposal of recycled water and sewage sludge in agricultural land. Food additive nanomaterials undergo various transformation and reaction processes, such as adsorption, aggregation-sedimentation, desorption, degradation, dissolution, and bio-mediated reactions in the environment. These processes significantly impact the transport and bioavailability of nanomaterials as well as their behaviour and fate in the environment. These nanomaterials are toxic to soil and aquatic organisms, and reach the food chain through plant uptake and animal transfer. The environmental and health risks of food additive nanomaterials can be overcome by eliminating their emission through recycled water and sewage sludge.

Valorization of clove (Syzygium aromaticum) by-products as potential stored grain protectants

Clove (Syzygium aromaticum) being a most valuable spice, produce stems and leaves as by-products during processing. This study aimed to valorize these by-products as potential grain protectants against rice weevils since it is a novel approach to reducing the post-harvest loss of rice and minimizing synthetic insecticide usage. The composition of clove stem and leaf essential oils was analyzed using gas chromatography-mass spectrometry. Accordingly, the contact repellent activity and fumigation mortality of essential oils were tested while computing the mortality percentage and LD50 values. The yield of stem essential oil (5.52%) was significantly higher than leaf essential oil (3.92%). Further, stem essential oil with a 100 µL dose showed the highest repellency (100.00 ± 0.00%) and mortality (96.67 ± 3.33%) while 50 and 75 µL doses caused similar mortality (83.30 ± 3.33%) after 5 days. The lowest LD50 (28.06 µL/L) was observed on day 5, indicating the higher toxicity of stem essential oil. Eugenol (73.73 and 82.56%), β-caryophyllene (24.84 and 16.67%), α.-humulene (0.82 and 0.33%), and 1S, CIS-calamenene (0.14 and 0.03%) were detected as the major components responsible for the insecticidal activity of stem and leaf essential oils. Hence, the valorization of clove by-products was successful as potential grain protectants, and clove stem essential oil could be the most effective alternative for rice weevil management.

Insulin resistance in a cohort of 5-15 year old children in urban Sri Lanka

BACKGROUND

South Asian populations develop insulin resistance from a young age. Poor intrauterine growth and increased rates of post natal growth predisposes to develop insulin resistance later in life. This study identifies insulin resistance and relation to birth weight among a group of 5-15 year old children of urban Sri Lanka.

METHODS

A cross sectional descriptive study, using two-stage probability proportionate cluster sampling technique. After a 12 h overnight fast, blood was drawn for fasting blood glucose and insulin. OGTT was performed with 2 h random blood glucose. Basic anthropometry was assessed and insulin resistance measured by HOMA-IR.

RESULTS

Of 309 children (boys 133) 13 (4.2%) were obese and 35 (11.3%) were overweight. Eight had impaired glucose homeostasis but no diabetes mellitus. The mean (SD) fasting insulin was 37.8 (37.9) and 32.5 (40.4) pmol/L in girls and boys respectively. 2 h post glucose insulin in girls and boys were 258 (324) and 152 (168) pmol/L respectively. The mean HOMA-IR was 1.1 (1.1) and 0.94 (1.2) for girls and boys respectively. The 4th quartile value of HOMA-IR for the whole population was 1.2 (95% CI 1.1, 1.3) and in obese children 2.26 (95% CI 2.0, 3.1). Fasting and 2 h insulin and HOMA-IR was not affected by birth weight but showed significant difference when compared across present BMI tertile with significantly high values in the highest tertile.

CONCLUSION

Although many children were able to control glucose within normal limits, evidence of early development of insulin resistance was seen. Children born small but became obese, had the highest risk of developing insulin resistance.

Distribution of obesity-related metabolic markers among 5-15 year old children from an urban area of Sri Lanka

BACKGROUND

Obesity-associated metabolic consequences are commonly seen among young South Asians.

OBJECTIVE

To assess the nutritional status, prevalence of metabolic derangements and to identify the validity of different obesity diagnostic criteria in the detection of metabolic derangements among 5-15 year old school children in the Colombo district of Sri Lanka. MATERIALS AND PROCEDURES: After a 12-hour overnight fast, blood was drawn for glucose, lipid profile and alanine amino transferase (ALT) enzyme. Oral glucose tolerance test (OGTT) was done with blood taken for random blood sugar 2 hours after glucose load. Height, weight, waist circumference (WC) and blood pressure were measured.

RESULTS

Nine hundred and twenty children were studied (boys, n = 547). Thirty-two (3.5%) were obese according to IOTF classification. Five (0.5%) and 57 (6.2%) children had systolic and diastolic hypertension. Twelve (1.3%) and three (0.3%) had impaired fasting glucose and 2-hour OGTT, respectively. One hundred and thirty-nine (15.1%) had hypercholesterolemia and 36 (3.9%) hypertriglyceridaemia. Two hundred and fifteen (23.3%) had low HDL. Fifteen (1.6%) had metabolic syndrome according to IDF definition. Two hundred and eighty-three (30.7%) had one metabolic derangement; 95 (10.3%) had two metabolic derangements; and 16 (1.7%) had three or more metabolic derangements. Sri Lankan BMI and WC obesity cut-offs had a higher sensitivity in detecting metabolic abnormalities than international cut-offs.

CONCLUSION

Metabolic derangements are prevalent in children who were detected to be non-obese by anthropometric measures, and clinicians should actively look and correct them. New research is needed to study the long-term effects on health.