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Volume 13, Issue 2, 2024

Online ISSN: 2182-1054

Volume 13 , Issue 2, (2024)

Published: 18.10.2024.

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01.12.2011.

Professional paper

Evaluation of test-kits for the detection of Escherichia coli O157 in raw meats and cattle faeces.

Escherichia coli O157 detection limits in artificially contaminated beef and cattle faeces samples were determined using Dynabeads anti E. coli O157 immunomagnetic beads, VIDAS-UP, VIDAS-ICE, and real-time PCR (GeneDisc and LightCycler) systems. Dynabeads anti-E. coli O157 immunomagnetic separation (IMS) and the GeneDisc cycler were the most sensitive methods, and could detect an initial 1 CFU in 25g beef samples after 6h of incubation in modified tryptone soya broth with novobiocin (mTSB+n) or buffered peptone water (BPW). The VIDAS-UP method could detect an initial 10 CFU, while VIDAS-ICE and the LightCycler methods could only detect an initial 100 CFU. Higher detection rates were achieved with 18 hour incubations, where an initial 1 CFU in a 25g sample could be detected with all five methods. For cattle faeces enrichments, Dynabeads anti-E. coli O157 IMS could detect an initial 1 CFU after a 6 h incubation in mTSB+n, while the VIDAS-UP and VIDAS-ICE methods could detect an initial 10 CFU and both PCR methods could only detect an initial 100 CFU. Detection rates were lower in BPW, compared to mTSB+n, with thresholds of 100 CFU for VIDAS-ICE, VIDAS-UP and GeneDisc methods, and >100 CFU for the LightCycler method.

Hilda Nyati, Annet Heuvelink, Caroliene Van Heerwaarden, Ans Zwartkruis

18.10.2012.

Professional paper

Food Engineering within Sciences of Food

The aim of this paper is to clarify the identity of food engineering in sciences of food. A short historical description of the evolution of the branch in the Anglo Saxon and the Continental educational systems is given. Furthermore, the distinction of basic definitions such as food science, food science and technology, food technology, and food engineering is made. Finally, the objectives of food engineering within the branch of sciences of food are described.

Athanasios Kostaropoulos

01.12.2011.

Professional paper

Bridging academic research and agribusiness in the recovery of byproducts from swine farming

Nowadays, food production has the challenging mission to encourage the growth of the rural economy assuring long term sustainability of their natural resources. The qualification of human resources and the generation of new knowledge are the main pillars that give sustainability to agribusiness. Animal protein production is one of the branches of the agribusiness sector. Swine production is recognized as an activity of high pollution potential, producing a large quantity of waste. This study aimed to identify the activities developed in partnership among academic, research and extension institutes in a midsize company of the agribusiness sector, more specifically a swine farm (São Roque Farm) in its sustainable restructuring. An exploratory and quantitative research was developed, which comprehended literature reviews, data collection and analysis of documents from the São Roque Farm. It was considered the period that includes the beginning of the sustainable restructuring of the property (2003) until December 2011. During the analysis of the Sustainable Restructuring Project, special attention was given to the readjustment of the wastewater treatment system and to the energy management and carbon credits, being innovative and pilot projects in the state of Santa Catarina. For this purpose, technologies and knowledge are being developed and applied in treatment of three routes: gaseous, liquid and solid. This pilot project allowed the development of applied studies at undergraduate, masters and PhD level and the main results achieved are the improvement of understanding and the achievement of technical and financial benefits by connecting agribusiness, academia and government research institutions.

Estela De Oliveira Nunes, Simone Perazzoli, Janaina Camile Pasqual

01.12.2011.

Professional paper

Challenges and Opportunities for the community of Food Sciences to contribute Towards a Society of Healthier Consumers and a Better World

Despite the tremendous scientific and technological achievements in the production of food, human well-being has not been served to a satisfactory extent. Millions of people are literally killing themselves by excessive eating or wrong use of food, leading to obesity and nutrition-related diseases. At the same time millions of people continue to suffer from lack of food, leading to starvation, malnutrition and death, often before reaching adult age. Parallel to striving for better-safer-healthier food, the community of Food Sciences is faced with the challenge to help educate the average consumer on how to select, handle, store and use food for safe and healthy eating. The need to reshape and reform public education to better serve this task is obvious. What is also obvious is the need for medical professionals to recognize healthy eating (and exercise) as the most valuable tool in preventive medical care. This perspective will concentrate on challenges and opportunities for Food Scientists/Engineers: to contribute towards a society of well-informed, self-protected, active and considerate citizens; to support public (food-related) education and actively participate in the fight against obesity and nutrition-related diseases; to intervene in decision making bodies and underline the importance of education on nutrition and food; to invent avenues and possibilities to contribute to the fight against world hunger; and all in all, to contribute towards a healthier world, a world that will not be split between hunger and obesity.

Harris N. Lazarides

01.12.2011.

Professional paper

Kinetics of Hydrolyzing Isolated Soy Protein by an Endopeptidase and its Conceptual Application in Process Engineering

A response study and the effects of different parameters (pH, temperature and enzyme dose) on kinetics of isolated soy protein hydrolysis by a trypsin-like endopeptidase (TL1) were conducted. Degree of hydrolysis (%DH) data varied at different times under different hydrolysis conditions. Fitting the kinetics data to Michaelis-Menten kinetics model did not result in reasonable kinetic parameters, which implied that Michaelis-Menten kinetics was invalid for such a hydrolysis process. A kinetics model proposed by (Gonzalez-Tello, Camacho, Jurado, Paez, & Guadix, 1994) was found to fit the kinetics curve well and resulted in acceptable model parameters. A simple simulation example was performed to demonstrate the concept of how the kinetics equation could be applied in process engineering.

Zebin Wang, Jason Lombardi, Jessica Shaffer, Ted Wong

01.12.2011.

Professional paper

Chia (Salvia hispanica) can be used to manufacture sugar-snap cookies with an improved nutritional value

Technologists and nutritionists are always looking for alternative ingredients to use in their formulations to improve functional and nutritional properties. Therefore, cookies using Chia (Salvia hispanica), a grain with high quality nutrients, were prepared. The nutritional value was determined by measuring the chemical composition, mineral content, and the fatty acid composition (saturated, monunsaturated, polyunsaturated, linoleic and linolenic acids). Data obtained from this chemical analysis was used to estimate the nutrients intake and compare them to the dietary reference intakes (DRIs). Cookies supplemented with chia flour contained signicantly more protein, fat, crude fiber, calcium, zinc, and alpha-linolenic (n-3) acid. It was estimated that the supplemented cookies would contribute to the corresponding DRIs in the range of 8.1-13.8% (children) and 6.5-11.0% (males/females) for calcium; and 14.0-18.0% (children) and 6.4-11.3 (males/females) for zinc. The addition of chia flour to the cookies resulted in a product sensorially acceptable with a better fatty acid profile (lower n-6/n-3). Supplemented cookies would contribute to alpha-linolenic DRI in the range of 65.9-134.5% (children), 49.4-100.9% (males), and 53.9-110.0% (females). Dietary intake of protein, fiber, calcium, zinc, and alpha-linolenic (n-3) acid could be increased by the consumption of sugar-snap cookies supplemented with chia flour.

V.A. Barrientos, A. Aguirre, Rafael Borneo

18.04.2011.

Professional paper

Effects of Pretreatments in Convective Dehydration of Rosehip (Rosa eglanteria)

The aim of this work was to experimentally determine drying curves for thin layer and bed drying of rosehip fruits, with and without pretreatments, to reduce processing times as a function of drying air operating variables, to propose dehydration kinetics of fruits and to determine its kinetic parameters for further use within drying simulation software. Fruits were pre-treated both chemically and mechanically, which included dipping the fruits in NaOH and ethyl oleate solutions; and cutting or perforating the fruit cuticle, respectively. Simulation models were then adopted to fit the kinetics drying data considering fruit volume shrinkage. These simple models minimized the calculation time during the simulation of deep-bed driers. Results show that pre-treatments reduced processing times up to 57%, and evaluated models satisfactorily predicted the drying of rosehip fruit. Effective mass diffusion coefficients were up to 4-fold greater when fruit was submitted to mechanical pretreatments.

Alejandra Mabellini, Elizabeth Ohaco, Carlos Alberto Márquez, Antonio De Michelis, Jorge Enrique Lozano

01.12.2011.

Professional paper

Influence of Organic Material and Biofilms on Disinfectant Efficacy Against Listeria monocytogenes

The effects of organic material and biofilm formation on the efficacy of Suma Tab D4 chlorine tablets and Suma Bac D10 quaternary ammonium compound (QAC) against Listeria monocytogenes was determined in suspension and on stainless steel and polystyrene surfaces according to standard disinfectant test methodology. Exposure to 200 and 740 mg L-1 QAC and to 150 mg L-1 active chlorine resulted in a > 5.0 log10 CFU mL-1 and > 5.0 log10 CFU/coupon reduction of six L. monocytogenes strains within one minute, in suspension tests, and on stainless steel surfaces, respectively. Additionally, there was a reduction by as much as 5 log10 CFU/coupon or 5 log10 CFU/well of reference strains EGDe and Scott A biofilms within five minutes on stainless steel and polystyrene surfaces. Organic material, added as bovine serum albumin at 0.3% (w/v) completely prevented the inactivation of L. monocytogenes in 150 mg L-1 chlorine, while reductions of only 0.6 +- 0.1 log10 CFU mL-1 were recorded in the presence of UHT milk at 3% (v/v). In contrast, reductions of 5 log10 CFU mL-1 were recorded within one minute on exposure to 740 mg L-1 QAC in the presence of 0.3% (w/v) bovine serum albumin and within two minutes in the presence of 20 % (v/v) UHT milk. Although Suma D4 chlorine tablets and Suma Bac D10 QAC are effective listericidal agents at recommended concentrations, Suma Tab D4 chlorine efficacy against L. monocytogenes is impaired by the presence of low concentrations of organic material, while Suma Bac D10 QAC maintains its listericidal activity in high organic loads.

Hilda Nyati, Rijkelt Beumer, Stijn Van der Veen, Wilma Hazeleger, Tjakko Abee

01.12.2011.

Professional paper

Effect of Egg White Utilization on the Physico-Chemical and Sensory Attributes of Protein-rich Yoghurt

High protein yoghurt was made from whole milk, fortified with egg white (30% v/v) and skim milk powder at 12% (w/v). Different yoghurt mixes, with albumin content of 15%, 30% and 45% (v/v), were prepared. The control was made from whole milk, fortified with skim milk powder at 12% (w/v). The blended premixes were pasteurized at 74ºC for 4 seconds, cooled and then inoculated with 3% (w/v) Direct Vat Set yoghurt starter culture at 45ºC. After fermentation for 3 hours in a water bath maintained at 46+-1C, product was cooled to 5ºC and then stored for 24 hours. The effect of the fortification on physico-chemical and sensory properties was investigated. Protein content increased to 8.50% at 45% egg white utilization. Susceptibility to wheying was reduced in egg-white fortified samples, without signicant difference in sensory attributes of the test samples compared to the control. Sensory analysis showed that yoghurt fortified with 45% egg white was organoleptically acceptable. The yoghurt was rated as having better sensory appeal as compared to the control.

Lilian A Gogo, Kennedy O. Gogo, Peter L. Shalo, Symon Maina Mahungu

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