Comparison of consumer perception and acceptability for steaks cooked to different endpoints: Validation of photographic approach

Charting the Future of E-Grocery: An Evaluation of the Use of Digital Imagery as a Sensory Analysis Tool for Fresh Fruits

While online grocery shopping has been rapidly expanding over the last several years, online sales of fresh produce have lagged far behind. One of the most significant contributing factors for this lag is the consumer’s inability to assess the quality of produce online. We hypothesized that this could be alleviated by machine vision technology. This study examines perceived sensory attributes derived from digital images of fresh fruits and compares them with sensory attributes obtained from the actual fruit. Digital images of fresh strawberries, cherry tomatoes, grapes, and blueberries were acquired using a high-resolution digital camera. Consumer panelists evaluated the appearance, texture, flavor, overall eating quality, and also determined purchase decision. Panel sizes ranging from 32 to 40 members (a total of 147) also conducted in situ evaluations of the different fruits. The paired t-test indicated that the mean results between pairs of image scores and in situ evaluation scores were statistically insignificant. The scores obtained for texture and overall eating quality showed some variability, but the scores for quality appearance were remarkably consistent revealing no difference across the evaluations of the various commodities. The results demonstrated that digital images can be utilized to effectively relay the appearance attributes of fresh produce. This finding is relevant for the industry, as the appropriate construction of real time images can help to build consumers’ trust in the quality of e-deliveries, nudge consumers to purchase fruits and vegetables, and increase the overall e-commerce acceptance for fresh produce. A discussion of the limitations and opportunities for improving the effectiveness of digital sensory analysis of fresh produce is provided.

Sensorial, color, lipid oxidation, and visual acceptability of dry-aged beef from young bulls with different fat thickness

The reduction in slaughter age with minimum fat and dry aging process improves meat tenderness, however, its shelf-life in display has not been studied. It was evaluated the sensorial, and the color, lipid oxidation, and visual acceptance in display of dry-aged beef (0, 14, and 28 days) from young bulls slaughtered with different subcutaneous fat thickness (2.00, 3.00, and 4.00 mm). Meat with 2.00 and 3.00 mm fat had higher acceptability than 4.00 mm (p < .05). Dry aging improved overall acceptability of consumers. Meat with 2.00 and 3.00 mm fat presented higher lightness and lipid oxidation values than 4.00 mm (p < .05) but similar visual acceptance was observed. Dry-aged beef (14 and 28 days) had lower lightness, but higher redness (p < .05) than not dry aged (0 days). Display reduced color over time, for all dry-aged treatments (p < .05). Dry aging process increased lipid oxidation but these values were below 2.00 mg/kg of malonaldehyde only in the first day of display. Dry aged for 14 days had similar visual acceptability to not dry-aged beef until the third day of display (p < .05). Shelf-life of 0, 14, and 28 days of dry aged was 5.41, 2.55, and 0.23 days. Despite of the increase in lipid oxidation and lightness, the sensorial and display acceptability of meat from young bulls was not prejudiced by the reduction in fat thickness. Beef dry-aged for 14 days was visually well accepted and could be displayed for 2.55 days without compromising acceptability.

Microbial Risk Assessment of Escherichia coli O157:H7 in Beef Imported from the United States of America to Taiwan

Outbreaks of foodborne illness caused by pathogenic Escherichia coli (E. coli) O157:H7, which are attributable to the consumption of undercooked beef, have occurred in many countries. In Taiwan, the production of domestic beef accounts for only 5% of the total amount of beef sold. Therefore, we applied different contextual assumptions to develop a quantitative microbial risk assessment of E. coli O157:H7 and evaluated the risk of illness in the Taiwanese population consuming beef imported from the United States of America. The probability distribution showed that, in males aged 19-65 years in the Taiwanese population, for example, when rare beef was consumed 100 servings, there was a 90% probability of randomly intaking seven colony forming units of E. coli O157:H7. When medium beef was consumed 10,000 servings, there was a 90% probability of randomly intaking two colony forming units of E. coli O157:H7. When the exceedance risk was 5%, the rate of foodborne illnesses caused by consuming rare beef contaminated with E. coli O157:H7 was 10-28 cases per 1 million individuals. For medium beef, this rate was 6-13 per 100 million individuals. Sensitivity analyses indicated that the amount of E. coli O157:H7 remaining in beef products after cooking was the most important risk factor, followed by the amount of beef products consumed. Proper cooking of imported beef consumed by the Taiwanese public reduces the incidence of foodborne disease to almost zero, without risk of harm to health.

Do Published Cooking Temperatures Correspond with Consumer and Chef Perceptions of Steak Degrees of Doneness?

The objective of this study was to assess consumer and chef perceptions and knowledge of beef degrees of doneness (DOD) as well as to measure the changes in cooked color over time related to DOD. Steaks from strip loins (M. longissimus lumborum) from each of 5 quality treatments were used for this study. Steaks were cooked to an endpoint temperature of either very-rare (54°C), rare (60°C), medium-rare (63°C), medium (71°C), well-done (77°C), or very well-done (82°C). L*, a*, and b* were evaluated at 0, 1, 2, 3, 6, 9, and 12 min post-cutting and digital pictures were taken immediately on an internal surface of the steak. Digital surveys for the evaluation of the images of the cooked steaks were created for consumers and chefs. There were time × DOD interactions (P < 0.05) for L*, a*, and b* values. For very-rare, rare, medium-rare, and medium, a* values increased (P < 0.05) over time. For L*, well-done and very well-done steaks became darker (P < 0.05) and very-rare, rare, and medium-rare steaks became lighter (P < 0.05) over time. Surveys indicated consumers determine DOD when cooking beef in their home primarily by using color, whereas chefs primarily use touch to determine DOD. There were no quality grade effects (P > 0.05) for DOD responses for steak pictures evaluated by consumers or chefs. Consumers identified the DOD of cooked steaks as the DOD that corresponds to published end-point temperatures 27 to 35% of the time. Chefs typically identified the DOD as 1 DOD higher than which the steaks were cooked for steaks cooked to medium or less and 1 DOD lower for steaks cooked to well-done and higher. This indicates differences exist in the perceptions of DOD between culinary professionals and consumers, and may contribute to decreased consumer satisfaction when ordering steaks in a restaurant.

Number of consumers and days of display necessary for the assessment of meat colour acceptability

Visual assessment is regarded as the gold standard to evaluate meat colour shelf-life, but it is costly and time consuming. To address this issue, this paper aims to evaluate the number of consumers and days of display that are necessaries in order to assess the colour shelf-life of meat, presented with different methods, all using images. Photographs of thirty-six lamb steaks were taken just after cutting (day 0) and on each of the following days until the 14th day of display under standardized conditions. Images were presented in three different manners: 1) with days of display and animals in random order (Random); 2) days of display in sequential and animals in random order (Sequential); and, 3) days of display and animals in sequential order (Animal); they were presented to 211 consumers who evaluated visual acceptability on a 9-point scale. At day zero, visual acceptability scores were the highest in Animal, followed by Sequential, and then by the Random (P < .05) method. Scores decreased over time for all methods tested (P < .05). The Random method presented the highest standard deviation; however, an increase in standard deviation among consumers along days of display was observed for all methods tested (P < .05). Shelf-life determined by regression varied according to the method of presentation (7.83, 7.00 and 7.54 days for Random, Sequential and Animal, respectively). A minimum number of 4 day points before and 4 day points after neutral scores had been reached (scores = 5.0) were necessary in order to obtain a robust model. The minimum number of required consumers (α = 0.05; d = 0.1 and β = 0.2 or 0.1) varied according to methodology: it was 81 to 109 consumers for Random, 69 to 92 for Sequential, and 55 to 74 for Animal. Our study indicates that an optimal number of days and evaluators can be calculated depending on the manner of sample presentation. These findings should be taken into account in further studies that aim to balance data reliability with the cost involved in meat colour analyses.

Changes in Lighting Source Can Produce Inaccurate Assessment of Visual Poultry Doneness and Induce Consumers To Eat Undercooked Ground Turkey Patties

Undercooked poultry is a potential source of foodborne pathogens, such as Salmonella and Campylobacter. The best way to avoid eating undercooked poultry is to use a food thermometer during cooking. However, consumers who cook poultry often use visual appearance for determining doneness, which relies on extrinsic factors, including lighting conditions. Because the United States recently mandated changes in lighting to promote energy conservation, this study evaluated the effect of lighting sources on consumer perceptions of doneness and willingness to eat cooked poultry patties. Consumers ( n = 104) evaluated validated photographs of turkey patties cooked to different end point temperatures (57 to 79°C) and rated the level of perceived doneness and willingness to eat each sample. Evaluations were conducted under different lighting sources: incandescent (60 W, soft white), halogen (43 W, soft white), compact fluorescent lamp (13 W, soft white), light-emitting diode (LED; 10.5 W, soft white), and daylight LED (14 W). Lighting changed perception of doneness and willingness to eat the patties, with some of the energy-efficient options, such as LED and halogen making samples appear more done than they actually were, increasing the willingness to eat undercooked samples. This poses a risk of consuming meat that could contain bacteria not killed by heat treatment. Recent changes in lighting regulations can affect lighting in homes that affects perceptions of poultry doneness, requiring that educators place extra emphasis on the message that properly using a meat thermometer is the only way to ensure meat is cooked to a safe end point temperature.

Distribution of serum levels of persistent organic pollutants, heterocyclic aromatic amine theoretical intake and nutritional cofactors in a semi-rural island population

Persistent organic pollutant (POP) exposure is strongly associated with negative health effects in humans. Heterocyclic aromatic amines (HAAs) are formed during high temperature cooking of foods (i.e. meat and fish). Human exposure to HAA is through food consumption and from similar food groups to POPs. A study of serum samples for POPs in a non-occupational exposed population (n = 149, age range 18-80 years, recruited in 2012) and comparison with estimated HAA daily intake calculations based on food diaries were undertaken. Three different age groups (group 1, 18-29 years; group 2, 30-44 years; and group 3, 45-80 years) were used to explore possible relationships between POP levels present in blood, HAA intake and nutritional cofactors. Significant differences (p < 0.05) between groups (1 and 3) for POP levels were found for p,p'-DDE, polychlorinated biphenyl (PCB) 153, PCB 138 and the sum of PCBs. A similar trend was found between groups 2 and 3 for PCB 153 and sum of PCBs. Significant differences were found between groups 1 and 3 and groups 2 and 3 for HAA intake., i.e. HAA intake was lowest in those of middle age, which may well reflect a different pathway of human exposure between HAA and POPs through the diet preferences.

Acid-labile protein-adducted heterocyclic aromatic amines in human blood are not viable biomarkers of dietary exposure: A systematic study

Heterocyclic aromatic amines (HCA) are carcinogenic mutagens formed during cooking of protein-rich foods. HCA residues adducted to blood proteins have been postulated as biomarkers of HCA exposure. However, the viability of quantifying HCAs following hydrolytic release from adducts in vivo and correlation with dietary intake are unproven. To definitively assess the potential of labile HCA-protein adducts as biomarkers, a highly sensitive UPLC-MS/MS method was validated for four major HCAs: 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx). Limits of detection were 1-5 pg/ml plasma and recoveries 91-115%. Efficacy of hydrolysis was demonstrated by HCA-protein adducts synthesised in vitro. Plasma and 7-day food diaries were collected from 122 fasting adults consuming their habitual diets. Estimated HCA intakes ranged from 0 to 2.5 mg/day. An extensive range of hydrolysis conditions was examined for release of adducted HCAs in plasma. HCA was detected in only one sample (PhIP, 9.7 pg/ml), demonstrating conclusively for the first time that acid-labile HCA adducts do not reflect dietary HCA intake and are present at such low concentrations that they are not feasible biomarkers of exposure. Identification of biomarkers remains important. The search should concentrate on stabilised HCA-peptide markers and use of untargeted proteomic and metabolomic approaches.