Determination of the persistence of dimetridazole, metronidazole and ronidazole residues in black tiger shrimp (Penaeus monodon) tissue and stability during cooking

The depletion of three banned nitroimidazole drugs (dimetridazole (DMZ), metronidazole (MNZ) and ronidazole (RNZ)) was investigated in black tiger shrimp (Penaeus monodon) following in-water medication. The highest concentrations of residues were measured immediately after the 24 h immersion (day 0). At this time, MNZ and MNZ-OH residues were measured in shrimp tissue samples at concentrations ranging from 361–4189 and 0.28–6.6 μg kg−1, respectively. DMZ and its metabolites HMMNI ranged in concentration between 31509–37780 and 15.0–31.9 μg kg−1, respectively. RNZ and HMMNI concentrations ranged 14530–24206 and 25.0–55 μg kg−1, respectively. MNZ, DMZ and RNZ were the more persistent marker residues and can be detected for at least eight days post-treatment. MNZ-OH was only detectable on day 0 following treatment with MNZ. HMMNI residues were only detectable up to day 1 (0.97–3.2 μg kg−1) or 2 (1.2–4.5 μg kg−1) following DMZ and RNZ treatment, respectively. The parent drugs, MNZ, DMZ and RNZ were still measureable on day 8 at 0.12–1.00, 40.5–55 and 8.8–18.7 μg kg−1, respectively. The study also investigated the stability of nitroimidazole residues under various cooking procedures (frying, grilling, boiling and boiling followed by microwaving). The experiments were carried out in shrimp muscle tissue containing both high and low concentrations of these residues. Different cooking procedures showed the impact on nitroimidazole residue concentration in shrimp tissuetheir concentration depleted significantly, but partially, by boiling and/or microwaving but the compounds were largely resistant to conventional grilling or frying. Cooking cannot therefore be considered as a safeguard against harmful nitroimidazole residues in shrimp.

Rethinking Rice Preparation for Highly Efficient Removal of Inorganic Arsenic Using Percolating Cooking Water

A novel way of cooking rice to maximize the removal of the carcinogen inorganic arsenic (Asi) is presented here. In conventional rice cooking water and grain are in continuous contact, and it is known that the larger the water:rice cooking ratio, the more Asi removed by cooking, suggesting that the Asi in the grain is mobile in water. Experiments were designed where rice is cooked in a continual stream of percolating near boiling water, either low in Asi, or Asi free. This has the advantage of not only exposing grain to large volumes of cooking water, but also physically removes any Asi leached from the grain into the water receiving vessel. The relationship between cooking water volume and Asi removal in conventional rice cooking was demonstrated for the rice types under study. At a water-to-rice cooking ratio of 12:1, 57±5% of Asi could be removed, average of 6 wholegrain and 6 polished rice samples. Two types of percolating technology were tested, one where the cooking water was recycled through condensing boiling water steam and passing the freshly distilled hot water through the grain in a laboratory setting, and one where tap water was used to cook the rice held in an off-the-shelf coffee percolator in a domestic setting. Both approaches proved highly effective in removing Asi from the cooking rice, with up to 85% of Asi removed from individual rice types. For the recycled water experiment 59±8% and 69±10% of Asi was removed, on average, compared to uncooked rice for polished (n=27) and wholegrain (n=13) rice, respectively. For coffee percolation there was no difference between wholegrain and polished rice, and the effectiveness of Asi removal was 49±7% across 6 wholegrain and 6 polished rice samples. The manuscript explores the potential applications and further optimization of this percolating cooking water, high Asi removal, discovery.

Domestic Cooking and Food Skills: A Review

Domestic cooking skills (CS) and food skills (FS) encompass multiple components, yet there is a lack of consensus on their constituent parts, inter-relatedness or measurement, leading to limited empirical support for their role in influencing dietary quality. This review assessed the measurement of CS and FS in adults (>16 years); critically examining study designs, psychometric properties of measures, theoretical basis and associations of CS/FS with diet. Electronic databases (PsychInfo), published reports and systematic reviews on cooking and home food preparation interventions (Rees et al. 2012 ; Reicks et al. 2014 ) provided 834 articles of which 26 met the inclusion criteria. Multiple CS/FS measures were identified across three study designs: qualitative; cross-sectional; and dietary interventions; conducted from 1998-2013. Most measures were not theory-based, limited psychometric data was available, with little consistency of items or scales used for CS/FS measurements. Some positive associations between CS/FS and FV intake were reported; though lasting dietary changes were uncommon. The role of psycho-social (e.g., gender, attitudes) and external factors (e.g. food availability) on CS/FS is discussed. A conceptual framework of CS/FS components is presented for future measurement facilitation, which highlights the role for CS/FS on food-related behaviour and dietary quality. This will aid future dietary intervention design.

Barriers and facilitators to cooking from 'scratch' using basic or raw ingredients: A qualitative interview study

Background: Previous research has highlighted an ambiguity in understanding cooking related terminology and a number of barriers and facilitators to home meal preparation. However, meals prepared in the home still include convenience products (typically high in sugars, fats and sodium) which can have negative effects on health. Therefore, this study aimed to qualitatively explore: (1) how individuals define cooking from ‘scratch’, and (2) their barriers and facilitators to cooking with basic ingredients.
Methods: 27 semi-structured interviews were conducted with participants (aged 18-58 years) living on the island of Ireland, eliciting definitions of ‘cooking from scratch’ and exploring the reasons participants cook in a particular way. The interviews were professionally transcribed verbatim and Nvivo 10 was used for an inductive thematic analysis.
Results: Our results highlighted that although cooking from ‘scratch’ lacks a single definition, participants viewed it as optimal cooking. Barriers to cooking with raw ingredients included: 1) time pressures; (2) desire to save money; (3) desire for effortless meals; (4) family food preferences; and (5) effect of kitchen disasters. Facilitators included: 1) desire to eat for health and well-being; (2) creative inspiration; (3) ability to plan and prepare meals ahead of time; and (4) greater self-efficacy in one’s cooking ability.
Conclusions: Our findings contribute to understanding how individuals define cooking from ‘scratch’, and barriers and facilitators to cooking with raw ingredients. Interventions should focus on practical sessions to increase cooking self-efficacy; highlight the importance of planning ahead and teach methods such as batch cooking and freezing to facilitate cooking from scratch.

The influence of socio-demographic, psychological and knowledge-related variables alongside perceived cooking and food skills abilities in the prediction of diet quality in adults: a nationally representative cross-sectional study

Background: Interventions to increase cooking skills (CS) and food skills (FS) as a route to improving overall diet are popular within public health. This study tested a comprehensive model of diet quality by assessing the influence of socio-demographic, knowledge- and psychological-related variables alongside perceived CS and FS abilities. The correspondence of two measures of diet quality further validated the Eating Choices Index (ECI) for use in quantitative research.
Methods: A cross-sectional survey was conducted in a quota-controlled nationally representative sample of 1049 adults aged 20–60 years drawn from the Island of Ireland. Surveys were administered in participants’ homes via computer-assisted personal interviewing (CAPI) assessing a range of socio-demographic, knowledge- and psychological-related variables alongside perceived CS and FS abilities. Regression models were used to model factors influencing diet quality. Correspondence between 2 measures of diet quality was assessed using chi-square and Pearson correlations.
Results: ECI score was significantly negatively correlated with DINE Fat intake (r = -0.24, p < 0.001), and ECI score was significantly positively correlated with DINE Fibre intake (r = 0.38, p < 0.001), demonstrating a high agreement. Findings indicated that males, younger respondents and those with no/few educational qualifications scored significantly lower on both CS and FS abilities. The relative influence of socio-demographic, knowledge, psychological variables and CS and FS abilities on dietary outcomes varied, with regression models explaining 10–20 % of diet quality variance. CS ability exerted the strongest relationship with saturated fat intake (β = -0.296, p < 0.001) and was a significant predictor of fibre intake (β = -0.113, p < 0.05), although not for healthy food choices (ECI) (β = 0.04, p > 0.05).
Conclusion: Greater CS and FS abilities may not lead directly to healthier dietary choices given the myriad of other factors implicated; however, CS appear to have differential influences on aspects of the diet, most notably in relation to lowering saturated fat intake. Findings suggest that CS and FS should not be singular targets of interventions designed to improve diet; but targeting specific sub-groups of the population e.g. males, younger adults, those with limited education might be more fruitful. A greater understanding of the interaction of factors influencing cooking and food practices within the home is needed.