Graham Purnell

The use of ‘hot wash’ treatments to reduce the number of pathogenic and spoilage bacteria on raw retail poultry

Abstract The development of a hot water treatment to reduce bacterial numbers on poultry carcasses is described. Initial trials identified suitable time/temperature for hot water immersion treatments and in subsequent work an experimental in-line processing unit was constructed and evaluated. Microbiological testing for organisms that are indicators for potential food spoilage (aerobic plate count) and human disease (Enterobacteriaceae, Campylobacter ) was performed to assess the benefit of the treatment. A treatment of 75 °C for 30 s significantly reduced the numbers of bacteria but the chicken skin tended to tear as the legs and wings were moved into position for a neat pack appearance (trussing). A treatment of 70 °C for 40 s, however, did not detrimentally affect the chicken skin. In addition, aerobic plate, Enterobacteriaceae and Campylobacter counts for treated samples were significantly lower than the controls ( P =0.005) for 8 days under typical chilled storage conditions.

A Review of Novel and Innovative Food Freezing Technologies

Freezing is a very well-established food preservation process that produces high quality nutritious foods with a long storage life. However, freezing is not suitable for all foods, and freezing can cause physical and chemical changes in some foods that are perceived as reducing the quality of either the thawed material or the final product. This paper reviews the many innovative freezing processes that are currently being researched and developed throughout the world to improve freezing conditions and product quality. Some innovative freezing processes (impingement and hydrofluidisation) are essentially improvements of existing methods (air blast and immersion, respectively) to produce far higher surface heat transfer rates than previous systems and thus improve product quality through rapid freezing. In these cases, the advantages may depend on the size of the product, since the poor thermal conductivity of many foods limits the rate of cooling in large objects rather than the heat transfer between the heat transfer medium and the product. Other processes (pressure shift, magnetic resonance, electrostatic, microwave, radiofrequency, and ultrasound) are adjuncts to existing freezing systems that aim to improve product quality through controlling the way that ice is formed in the food during freezing. Another alternative is to change the properties of the food itself to control how ice is formed during freezing (such as in dehydrofreezing and the use of antifreeze and ice-nucleation proteins).

Robotic equipment in the meat industry

Robotic technology is beginning to find uses in the meat processing industry. This paper attempts to describe the potential benefits and some of the problems in implementing robots for meat processing. An overview of some of the robotic equipment available and in development for beef, pork, lamb, poultry, fish and seafood processing is given. Standard industrial robots already perform meat industry tasks involving regular and uniform products and processes. Robotic automation is emerging for more skilled tasks but is not yet fully accepted or implemented in the meat industry.

Combined steam and ultrasound treatment of broilers at slaughter: A promising intervention to significantly reduce numbers of naturally occurring campylobacters on carcasses

Steam or hot water decontamination treatment of broiler carcasses is hampered by process limitations due to prolonged treatment times and adverse changes to the epidermis. In this study, a combination of steam with ultrasound (SonoSteam®) was investigated on naturally contaminated broilers that were processed at conventional slaughter speeds of 8,500 birds per hour in a Danish broiler plant. Industrial-scale SonoSteam equipment was installed in the evisceration room, before the inside/outside carcass washer. The SonoSteam treatment was evaluated in two separate trials performed on two different dates. Numbers of naturally occurring Campylobacter spp. and TVC were determined from paired samples of skin excised from opposite sides of the breast of the same carcass, before and after treatments. Sampling was performed at two different points on the line: i) before and after the SonoSteam treatment and ii) before the SonoSteam treatment and after 80 min of air chilling. A total of 44 carcasses were examined in the two trials. Results from the first trial showed that the mean initial Campylobacter contamination level of 2.35 log₁₀ CFU was significantly reduced (n=12, p<0.001) to 1.40 log₁₀ CFU after treatment. A significant reduction (n=11, p<0.001) was also observed with samples analyzed before SonoSteam treatment (2.64 log₁₀ CFU) and after air chilling (1.44 log₁₀ CFU). In the second trial, significant reductions (n=10, p<0.05) were obtained for carcasses analyzed before (mean level of 2.23 log₁₀ CFU) and after the treatment (mean level of 1.36 log₁₀ CFU). Significant reductions (n=11, p<0.01) were also found for Campylobacter numbers analyzed before the SonoSteam treatment (2.02 log₁₀ CFU) and after the air chilling treatment (1.37 log₁₀ CFU). The effect of air chilling without SonoSteam treatment was determined using 12 carcasses pre- and postchill. Results showed insignificant reductions of 0.09 log₁₀ from a mean initial level of 2.19 log₁₀ CFU. Numbers of TVC before treatments ranged between 3.47 and 4.79 log₁₀ CFU. In all cases, TVC was significantly (p<0.001, n=45 in each trial) reduced by approximately 0.7 log₁₀ CFU. An authorized sensory panel at the Danish Veterinary and Food Administration concluded that broiler carcasses treated with SonoSteam were acceptable for purchase. These conclusions were based on organoleptic differences (smell, skin/meat consistency, texture and color) of treated vs. untreated carcasses. Results obtained from this study suggest that steam-ultrasound treatment of carcasses at broiler processing plants can significantly reduce numbers of Campylobacter on naturally contaminated broilers.

A Critical Review of Dehydrofreezing of Fruits and Vegetables

Freezing is a very well established food preservation process that produces high-quality nutritious foods that offer the advantage of a long storage life. However, freezing is not suitable for all foods, and freezing does cause physical and chemical changes in many foods that are perceived as reducing the quality of the thawed material. Many innovative freezing processes are currently being researched and developed throughout the world to overcome these problems. One of these is dehydrofreezing. Dehydrofreezing is an adjunct to freezing in which a food is first dehydrated to a desirable moisture content and then frozen. It is particularly suited to fruits and vegetables. Since fresh fruits and vegetables contain more water than meat, and their cellular structure is less elastic, they are prone to more damage during freezing than meat. Removing some of the water prior to freezing theoretically allows the ice crystals to form and expand without damaging the cellular structure. Reducing the water content prior to freezing also has the potential to reduce the freezing time, the initial freezing point, and the amount of ice formed within the product. Despite being often cited as a new, novel or emerging technology, the concept of dehydrofreezing was developed in the 1940s. However, it has remained a niche process being commercially applied to products such as potatoes, carrots, and onions. In recent years there has been renewed interest in dehydrofreezing, and this review looks at the most recent innovations in dehydrofreezing research.

Robot deboning for beef forequarters

Initial development of a robotic meat cutting system based on force feedback control and continuous path planning is described. Forequarter beef cutting is attempted where each carcass processed will be compared to a database containing cut information for previously processed beef carcasses. Using the database information, cut start and end points can be defined along with initial path direction for each cut. A robot then drives a powered knife through the carcass utilising force feedback control to follow bone profiles, thus removing meat from the forequarter. An original cutting scheme suitable for robotic butchery of a beef forequarter is defined, along with a notation scheme for describing the cutting procedures.

Robots for the meat industry

Discusses research carried out by the Advanced Manufacturing and Automation Research Centre [AMARC], University of Bristol into the automation of two areas of meat production, the butchery of half carcasses into main joints and the evisceration of whole carcasses. Describes how the robotic butchery process requires sensing, determination of cut‐paths and trajectories for the robot, mechanical cutting using appropriate tools and the ability to transport, manipulate and hold each carcass during cutting and how each of these areas bas been integrated into a practical system. Also describes the system developed for robotic evisceration. Concludes that this research work has led to two industrial demonstrator systems for processing meat carcasses which have had encouraging response from potential customers.

An evaluation of improvements in carcass hygiene through the use of anal plugging of pig carcasses prior to scalding and dehairing.

This study evaluated the effect of plugging the anuses of pork carcasses prior to scalding and dehairing on Enterobacteriaceae contamination on pork carcass surfaces. Results showed that Enterobacteriaceae counts around the anuses of unplugged carcasses increased by 1.15 log CFU/cm(2) after the scalding and dehairing process, while counts in the same sample area from plugged carcasses showed no significant change in Enterobacteriaceae numbers. The percentage of plugged carcasses with Enterobacteriaceae counts (measured around the anuses of carcasses) below the level of detection (<1 log) was 23.5%, whereas only 2.9% of unplugged carcasses were below this level. In the context of a multiple-hurdle approach where incremental reductions in microbiological counts may be seen as positive, anal plugging may have particular benefit.

A new algorithm for pick-and-place operation

Purpose – This paper aims to represent a novel framework for optimization of robotic handling from disarray to structure where the products are randomly distributed on a surface, the initial location of the products are known (with the aid of image processing, laser position sensors, etc.) and there is a set of final positions for the products.Design/methodology/approach – Pick‐and‐place is one of the main solutions especially for the food products where the products are prone to damage, have adhesive surfaces and the grippers can be complicated. The aim of this paper is to maximize the utilization of the pick‐and‐place robotic system. In order to do so the handling process is modelled mathematically and the pick‐and‐place problem is formulated based on assignment problem where Hungarian algorithm is utilized to minimize the total distance travelled by the robot. Furthermore, a simulation program is developed to demonstrate the possible improvements of the algorithm in comparison with the existing algorit...

Introducing a new 3D ordering process for discrete food products using food categorisation

Purpose – This paper aims to introduce and identify a new 3D handling operation (bin picking) for natural discrete food products using food categorisation.Design/methodology/approach – The research shows a new food categorisation and the relation between food ordering processes and food categories. Bin picking in the food industry needs more flexible vision software compared to the manufacturing industry in order to decrease the degree of disarray of food products and transfer them into structure.Findings – It has been shown that there are still manual operated ordering processes in food industry such as bin picking; it just needs new ideas of image processing algorithms such as active shape models (ASMs) on its development in order to recognise the highly varying shapes of food products.Research limitations/implications – This research was aimed at locating a new ordering process and proving a new principle, but for practical implementation this bin picking solution needs to be developed and tested furth...