Food Industry Equipment Research Articles

Guiding Criteria for Hygienic Design of Food Industry Equipment

AbstractEquipment design for food industry should consider, in addition to performance, cost and quality requirements, further aspects regarding to hygiene and food safety. This paper discusses how information associated with hygiene aspects can be used as orientation criteria for equipment design for food industry. The study was based on specialized literature and national and international standards to establish valuation criteria for hygienic design. Eighty‐five criteria were established, grouped into six orientation classes, as follows: processes, materials, geometry, accessories, sealing and others. The criteria were validated through their application in a company which produces concentrated fruit juice, demonstrating how problems could have been avoided by using this valuation method.Practical ApplicationsThis work provides a contribution to food industry equipment in order to understand how to identify, classify and store the best practices for hygienic design of food processing equipment. In very specific sectors such as food equipment industry, the knowledge related to the equipment design is usually captured in a tacit manner. This paper provides a reflection on this subject and shows a way to organize this knowledge.

Sub-lethal concentrations of Muscari comosum bulb extract suppress adhesion and induce detachment of sessile yeast cells

The formation of yeast biofilm on food industry equipment can lead to serious hygiene problems and economic losses due to food spoilage and equipment impairment. This study explored the ability of a sub-lethal concentration of the bulb extract of Muscari comosum to modulate adhesion of Candida albicans and subsequent biofilm development by this fungus. The HPLC profile of the ethanolic bulb extract showed phenolic constituents, which were found to undergo Folin-Ciocalteu reagent reduction. Prior to the adhesion tests, it was shown that up to 4000 mg l−1 of natural extract did not adversely affect fungal growth nor did it act as a carbon energy source for C. albicans. Mathematical models predicted that 4000 mg l−1 and 700 mg l−1 of bulb extract would cause more than 98% reduction in fungal coverage on abiotic surfaces, without killing the planktonic cells. When added to C. albicans biofilm, the natural extract was shown to induce the dispersion of sessile cells in a dose-dependent manner.

ANTIBACTERIAL ACTION OF ZINC OXIDE NANOPARTICLES AGAINST FOODBORNE PATHOGENS

ABSTRACTThe current spreading of nanomaterial applications supports the search for further possible functions of theses diminutive particles. The antibacterial potentiality of zinc oxide (ZnO) nanoparticles (NPs), compared with conventional ZnO powder, against nine bacterial strains, mostly foodborne including pathogens, was evaluated using qualitative and quantitative assays. ZnO NP was more efficient as antibacterial agent than powder. Gram‐positive bacteria were generally more sensitive to ZnO than Gram negatives. The exposure of Salmonella typhimurium and Staphylococcus aureus to their relevant minimal inhibitory concentrations from ZnO NP reduced the cell number to zero within 8 and 4 h, respectively. Scanning electron micrographs of the treated bacteria with NPs exhibited that the disruptive effect of ZnO on S. aureus was vigorous as all treated cells were completely exploded or lysed after only 4 h from exposure. Promising results of ZnO NP antibacterial activity suggest its usage in food systems as preservative agent after further required investigations and risk assessments.PRACTICAL APPLICATIONSFoodborne pathogen invasion is still a recurrent serious problem facing researchers and food industry overseers. The introduction of novel powerful antimicrobial agents is of great importance for the control of pathogenic bacteria, especially antibiotic‐resistant strains. Zinc oxide (ZnO) nanoparticle (NP) could be one of these potential alternatives. This study focused on ZnO NP because of its increasing presence in many marketable products and that supports its application in food industries as a reasonably safe agent. The demonstrated antibacterial activity of ZnO NP recommends its possible application in the food preservation field; otherwise it can be applied as a potent sanitizing agent for disinfecting and sterilizing food industry equipment and containers against the attack and contamination with foodborne pathogenic bacteria.

Polyoxyethylene alkyl and nonyl phenol ethers complexation with potato starch

Starchy soil removal efficiency when cleaning food industry equipment can be affected by surfactant–starch complexes. Polyoxyethylene alkyl and nonyl phenol ethers complexation with potato starch has been studied by surface tension measurements. All surfactants assayed yield inclusion complexes with starch after a critical concentration of association was achieved. No starch saturation was observed throughout complexation until micellization, with bound surfactant being proportional to the total added surfactant. This bound/total surfactant ratio and the critical concentration of association seemed to depend mainly on the surfactant alkyl chain length. Unlike fatty alcohol ethoxylates, the nonyl phenol ethoxylate was feebly bound likely caused by its aromatic moiety. Binding isotherms and Scatchard plots suggested surfactants positive cooperative and non-cooperative binding with amylose and amylopectin respectively. Phosphate buffer raised surfactants binding capacity, ascribed either to an increase in cooperativity or to a reduction in the number of glucose units required to bind a surfactant molecule.

Self-Tuning Type-2 PID control system and its application

This study proposes an adaptive control method of a weigh feeder. A weigh feeder dispenses material into a process at a precise rate, and it has been employed in industries, e.g., process control, cement manufacturing plants, food industry equipment, and so on. To introduce advanced control into industries, self-tuning controllers are designed for controlling a weigh feeder. Three difference controllers are designed; one degree-of-freedom (1DOF) PID, 1DOF PD, and two degree-of-freedom (2DOF) PD controllers, and these control methods are compared through experimental results. Because discharged mass is measured by employing loss-in-weight method, a reference input followed by a plant output is ramp-type, and a type-2 control system has to be designed. Since the controlled object includes an integrator, a type-2 control system can be obtained by using 1DOF PID controller. In design of 2DOF PD control, a pre-compensator is designed to eliminate steady-state velocity error. Further, to be compared with 1DOF PID and 2DOF PD control, a 1DOF PD controller is designed. In this paper, PID and PD controllers are designed on the basis of generalized minimum variance control (GMVC) to obtain useful control methods adopted in industries. In design of the proposed control methods, GMVC can be replaced precisely with a simple PID or PD controller, and advanced control performance can be obtained. Experimental results are shown and compared, and the effectiveness of the proposed design method is shown.

New biodegradable antifriction grease

The paper presents the composition and the process of production of the new grease containing exclusively environmentally safe biodegradable components such as rape oil, vegetable oil tar, inedible fat as well as natural and artificial silicates. The grease is operable within 0–160°C and intended for friction units of light and food industry equipment.

Ultrasonic Cleaning of Conveyor Belt Materials Using Listeria monocytogenes as a Model Organism

Persistent Listeria monocytogenes contamination of food industry equipment is a difficult problem to solve. Ultrasonic cleaning offers new possibilities for cleaning conveyors and other equipment that are not easy to clean. Ultrasonic cleaning was tested on three conveyor belt materials: polypropylene, acetal, and stainless steel (cold-rolled, AISI 304). Cleaning efficiency was tested at two temperatures (30 and 45°C) and two cleaning times (30 and 60 s) with two cleaning detergents (KOH, and NaOH combined with KOH). Conveyor belt materials were soiled with milk-based soil and L. monocytogenes strains V1, V3, and B9, and then incubated for 72 h to attach bacteria to surfaces. Ultrasonic cleaning treatments reduced L. monocytogenes counts on stainless steel 4.61 to 5.90 log units; on acetal, 3.37 to 5.55 log units; and on polypropylene, 2.31 to 4.40 log units. The logarithmic reduction differences were statistically analyzed by analysis of variance using Statistical Package for the Social Sciences software. The logarithmic reduction was significantly greater in stainless steel than in plastic materials (P < 0.001 for polypropylene, P = 0.023 for acetal). Higher temperatures enhanced the cleaning efficiency in tested materials. No significant difference occurred between cleaning times. The logarithmic reduction was significantly higher (P = 0.013) in cleaning treatments with potassium hydroxide detergent. In this study, ultrasonic cleaning was efficient for cleaning conveyor belt materials.

Metodologia para determinação de digluconato de clorhexidina em carcaças de frango utilizando CLAE - par iônico e avaliação de resíduos durante a refrigeração e congelamento

O uso do digluconato de clorhexidina (DGCH) na higienizacao de equipamentos e instalacoes na industria de alimentos e o interesse de aplicacao deste produto como sanitizante em carcacas de frango indicam a necessidade da avaliacao de residuos no alimento. Um metodo por cromatografia liquida de alta eficiencia (CLAE) com pareamento de ions, incluindo extracao com eter etilico em meio alcalino, foi desenvolvido para determinacao de clorhexidina em carne de frango. O limite de quantificacao do metodo (0,6mg/g) e a recuperacao media em carcaca (75% - CV 10%), em pele (72% - CV 7%) e na musculatura (82% - CV 8%) foram considerados adequados aos propositos do metodo. As analises de carcacas e pele tratadas, mantidas refrigeradas ou congeladas, permitiu constatar que ocorreu uma pequena reducao nos niveis residuais de DGCH durante o periodo de armazenamento. Como provaveis causas desta diminuicao devem ser considerados a interacao com componentes polares da matriz, a perda juntamente com os fluidos liberados dos tecidos durante o armazenamento refrigerado ou no descongelamento de carcacas inteiras e a degradacao da clorhexidina. A ausencia deste sanitizante na musculatura apos o armazenamento refrigerado indica que nas condicoes empregadas, o DGCH nao atravessa a barreira da pele.

Elimination of adhering bacteria from surfaces by pulsed laser beams.

As an alternative to the use of chemicals for cleaning and disinfecting surfaces of equipment in food industry, the efficacy of pulsed laser beams for removal and killing of adherent bacteria from stainless steel surfaces was assessed. Escherichia coli biofilms were produced under dynamic conditions in diluted nutritive medium incubated at 37 degrees C for 24 h. Influence of energy density and number of shots were tested at three wavelengths (1064, 532 and 355 nm). With one 20 ns pulse, results range from 3.5 decimal reductions of the microbial load with < or = 50 MW cm-2 without visible alteration of the surface, to more than 6 decimal reductions with < or = 600 MW cm-2. The measured effect was largely attributed to removal of the micro-organisms and transfer to the surrounding air. The treatment could therefore be improved with respect to the numbers remaining associated with the surface by venting.

Cross-flow filtration of contaminated liq — esp. from cleaning equipment in food industry: SCHWEIZEIDGENOSSENSCHAFT EIDGENOSSISCHE 93.07.15 93CH-002198 J01 P43 (96.06.14) B08B 3/14, B01D 36/04, 61/16 Addnl.Data: HENCK M A

Cross-flow filtration of contaminated liq — esp. from cleaning equipment in food industry: SCHWEIZEIDGENOSSENSCHAFT EIDGENOSSISCHE 93.07.15 93CH-002198 J01 P43 (96.06.14) B08B 3/14, B01D 36/04, 61/16 Addnl.Data: HENCK M A

Observations on the influence of cleaners on material corrosion in the food industry

Characterization studies have been carried out on cleaners and sanitizing processes that cause corrosion on AISI 304 and AISI 316 stainless steels and on pure aluminum—materials used in food industry equipment. Corrosion phenomena were evaluated by means of electrochemical polarization measurements, and surface deterioration was studied with the use of scanning electron microscopy. The results indicated a relation between corrosion potentials and damage morphology, which depended on the alkaline or acidic nature of the environment of the cleaning products and their effects on the surface condition of materials.