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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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01.12.2016.

Professional paper

Rheological properties of traditional balsamic vinegar: New insights and markers for objective and perceived quality

The molecular structure of Traditional Balsamic Vinegar (TBV) undergoes shear-induced and time-dependent jamming transitions due to the high solute concentration and self-assembling phenomena of high molecular size melanoidins with very-long relaxation times (12 years at least or more than 25). The purpose of this work was to perform a descriptive and quantitativeevaluation of relationships between rheological properties, vinegar composition, and perceptual assessment of sensory properties according to the official sensory procedure. With this aim, vinegars having quality traits matching legal requirements for the PDO designation were analyzed for their reducing sugars (glucose and fructose), volatile acidity, fixed acidity, pH, Brix degree, and density as well as for their flow behaviour and dynamic viscosity over a wide range of shear rates. Results showed that flow behaviour of TBV was affected by jamming properties over wide-scale ranges of shear rate producing flow instability below a shear rate of 60s-1. Homogeneous, continuous flow was found at medium-high shear rates with thickening and/or thinning traits. A common onset for the structure scaling was mathematically estimated to occur close to when the density was 1.32 gmL-1. Comparative analysis of rheological, compositional and sensory properties suggested that the colloidal jamming of the vinegar melanoidins dominated the total olfactive and gustative stimuli, and determined the classification of the vinegars that had a higher dynamic viscosity but more homogeneous flow as being of the highest commercial quality category. A robust statistical model was proposed encoding for the top-down decision-making process for quality assignment according to the official sensory procedure, using composition and flow properties as predictor variables. 

Pasquale M. Falcone, Elisa Sabatinelli, Federico Lemmetti, Paolo Giudici

01.12.2016.

Professional paper

Microbial quality and shelf life prediction of vacuum-packaged ready to eat beef rounds containing gum arabic

Research has shown that gum arabic from Acacia senegal var. kerensis can be used in beef rounds, at a level of 2.5% of the formulated product weight, as a binder and texture modifier. However, the effect of gum arabic addition on the microbial quality and shelf life of the resulting meat product has not yet been reported. Thus, the objective of this work was to study the microbial quality of beef rounds containing 2.5% gum arabic and to study shelf life based on the growth parameters of Total Viable Counts (TVC) and Lactic Acid Bacteria (LAB). Beef round samples were injected at 30% with curing brines containing gum arabic and cooked through boiling. The growth kinetics of LAB and TVC were studied for vacuum packaged sliced beef round samples stored at 7 oC and 15 oC for a period of 21 days. Baranyi and modified Gompertz models were used to fit the LAB and TVC data obtained using DMFit. Results of microbial analysis indicated that coliforms, yeasts and molds as well as pathogenic bacteria; Salmonella, Escherichia coli, and Staphylococcus aureus, were below detection limit. In addition, TVC and LAB were found to be 1.87 ± 1.09 and 1.25 ± 0.75 Log 10 CFU g-1, respectively. The results of accuracy analysis showed that both the Baranyi and modified Gompertz models were adequate in representing the bacterial growth in beef rounds injected with curing brines containing gum arabic. The predicted shelf life was found to be between 84.3 – 88.1 h and 158.0 – 173.1 h at 15 oC and 7 oC, respectively.

Johnson K. Mwove, Symon M. Mahungu, Lilian A. Gogo, Ben N. Chikamai, Mary Omwamba

01.12.2016.

Professional paper

Optimization of microwave vacuum drying parameters for germinated lentils based on starch digestibility, antioxidant activity and total phenolic content

The aim of this study was to optimize the processing parameters of pulse mode microwave-vacuum drying of germinated green and red lentils (CDC Greenland and CDC Maxim) and investigate the changes in their total phenolic content (TPC), total antioxidant activity (TAA) and in-vitro starch digestibility (SD). The lentils were germinated for 5 days and dried by a pulse mode microwave-vacuum method, using 2 s to 8 s out of 10 s pulsed mode at 2000W microwave power and varying the vacuum pressure level between 15 and 45 kPa. In-vitro starch digestibility increased significantly with increased microwave power level. The TPC and TAA appeared to vary distinctively in the two varieties of selected lentils. Vacuum pressure levels did not significantly (p>0.05) affect any responses. Green lentils could be dried at 8 s microwave power and 45 kPa vacuum pressure and red lentils could be dried at 5.5 s microwave power and 42.19 kPa vacuum pressure. The microwave-vacuum drying showed great potential for the drying of germinated lentils.

Robbarts Nongmaithem, Venkatesh Meda

18.04.2016.

Original scientific paper

Towards the development of a common starter culture for fufu and usi (edible starch): Screening for potential starters

Fermented cassava products like fufu and usi are important staple foods in many African homes. Natural fermentation time is usually long resulting in slower acidification and inconsistent nutritional composition of products which could be overcome with the use of starter culture. However, most available starters are used for single food fermentation and are uneconomical. This necessitates the development of a starter culture for multiple related food products to reduce cost. Hence, this study aimed at screening for potential starters in the development of a common starter culture for fufu and usi. Fresh, peeled, chipped and grated cassava tubers were spontaneously fermented and lactic acid bacteria were isolated from the fermenting mash at 24 hour intervals. Ninety eight (98) isolates were randomly picked. Lactobacillus plantarum had highest occurrence (50.0%) in both fermentations. All selected isolates did not hydrolyze starch, but produced linamarase and pectinase. Fermenting pH ranged between 6.50 and 3.58 during 72 hours fermentation. Lactic acid concentration ranged from
1.10 g/L to 1.78 g/L at 24 hours, 1.22 g/L to 2.45 g/L at 48 hours and 0.57 g/L to 2.55 g/l at 72 hours. The highest hydrogen peroxide concentration produced was 629 µg/L at 24 hours while the least was 136 µg/L at 72 hours. 1.08 g/L of diacetyl was the least concentration produced at 24 hours while the highest was 2.86 g/L at 48 hours. Five potential starters were identified as Lactobacillus pentosus F2A, L. plantarum subsp. argentolarensis F2B, L. plantarum F2C, L. plantarum U2A and L. paraplantarum U2C.

Kubrat Oyinlola, Anthony A. Onilude, Oluwaseun E. Garuba

16.04.2016.

Original scientific paper

The Atlantic diet – Origin and features

Despite globalization there still are food patterns which are clearly differentiated from one region to another in Europe and elsewhere. In this study the Atlantic Diet is considered as the traditional diet in Portugal and Galicia, a region in northwest Spain. This paper aims to contribute to a better understanding of the Atlantic Diet food pattern in order to fully exploit the potential of this Atlantic gastronomical heritage. The background of the Atlantic Diet concept, the characterization of Atlantic Diet foods and a compilation of scientific findings related to the consumption of these foods are covered. A brief description of the Mediterranean Diet, the primitive pattern and the updated Mediterranean pyramid are also included in order to aid understanding of the globalization of this previously local health food pattern.
Final remarks and suggestions for further studies are made. 

Manuela Vaz Velho, Rita Pinheiro, Ana Sofia Rodrigues

18.04.2016.

Original scientific paper

Developing and delivering food systems training programs for 21st century audiences

Expectations for training programmes today are very different from expectations for training programmes in the past, because today’s audiences are not only multigenerational, but the younger generations learn in distinctly different ways from older, more traditional audiences. To meet the needs of these multigenerational audiences, the Auburn University Food Systems Institute (AUFSI) has developed on-demand, online courses that offer a variety of ways for learners to interact with training materials. For example, a typical course may offer not only traditional text, but audio, video, simulations, and more. In addition, AUFSI has developed supporting educational tools such as interactive virtual tours and video games. This approach to creating courses is a response to the different levels of experiences of the generations as well as different expectations of how materials should be delivered. In order to be effective, training materials need to be designed to appeal to this multigenerational audience. Traditionalists (born before 1946) prefer face-to-face training programmes. Baby Boomers (born 1946-1964) are more accepting of technology. Generations X (born 1965-1980), Y (born 1981- 2000) and C (born after 2000), however, expect to receive training at their convenience, to have it delivered electronically, and to be entertained as well as educated.

Troy Hahn, Patricia Curtis

18.04.2016.

Original scientific paper

A food recall case study in Australia – Towards the development of food safety applications for consumers

Changes in consumer attitudes, behaviours and purchasing preferences towards different types of food highlight the increased demand for better quality information on safety, quality and provenance of food products and on sustainability of food production processes. These changes offer both new opportunities and risks for food producers who require mechanisms to better understand and respond to changing consumers’ decision-making trends on food. In the area of food safety, investigation of consumer and producer responses during recall incidents provide an opportunity to holistically understand existing information flows and elicit user requirements necessary for the development of more effective consumer food safety applications. This paper reports on a case study conducted with an Australian premium manufacturing company that experienced a food recall in 2014. The investigation confirms that current Australian food recall response mechanisms do not guarantee a closed loop of communication with all purchasers of a recalled product. It also highlights that producers still face difficulties in understanding how best to effectively understand and respond to different types of consumers. It emerges that recovery from a food incident relies on many factors including pre-existing brand reputation, effective information management, control mechanisms and supply chain partner response. From a consumer perspective, it is evident that consumers’ responses are influenced by various factors that require sensitivity around the choice of information modality and information platform adopted to enhance communications during food recall. The paper highlights the need for further research into understanding consumer food safety behaviours post-purchase to improve the development of consumer food safety applications.

Adeola Bamgboje-Ayodele, Leonie Ellis, Paul Turner

18.04.2016.

Original scientific paper

The emulsifying effect of biosurfactants produced by food spoilage organisms in Nigeria

Food spoilage organisms were isolated using standard procedures on Nutrient Agar, Cetrimide Agar and Pseudomonas Agar Base (supplemented with CFC). The samples were categorized as animal products (raw fish, egg, raw chicken, corned beef, pasteurized milk) and plant products (vegetable salad, water leaf (Talinium triangulare), boiled rice, tomatoes and pumpkin leaf (Teifairia occidentalis).They were characterised as Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas stutzeri, Burkholderia pseudomallei, Serratia rubidaea, Corynebacterium pilosum, Bacillus subtilis, Bacillus mycoides, Bacillus laterosporus, Bacillus laterosporus, Serratia marcescens, Bacillus cereus, Bacillus macerans, Alcaligenes faecalis and Alcaligenes eutrophus. Preliminary screening for biosurfactant production was done using red blood haemolysis test and confirmed by slide test, drop collapse and oil spreading assay. The biosurfactant produced was purified using acetone and the composition determined initially using Molisch’s test, thin layer chromatography and gas chromatography mass spectrometry. The components were found to be ethanol, amino acids, butoxyacetic acid, hexadecanoic acid, oleic acid, lauryl peroxide, octadecanoic acid and phthalic acid. The producing organisms grew readily on several hydrocarbons such as crude oil, diesel oil and aviation fuel when used as sole carbon sources. The purified biosurfactants produced were able to cause emulsification of kerosene (19.71-27.14%) as well as vegetable oil (16.91-28.12%) based on the emulsification index. This result suggests that the isolates can be an asset and further work can exploit their optimal potential in industries.

christianah ogunmola, Olusimbo O. Aboaba

18.04.2016.

Original scientific paper

Innovation and knowledge transference in a cluster user-driven innovation perspective – the Inovcluster experience

Our purpose with this article is to show the importance of assessing trends and promoting innovation in a real business context, through a cluster ecosystem, mainly composed of micro-enterprises in the agro-industrial Portuguese sector. As many studies show, Inovcluster (which has 158 associates, from which 120 are enterprises) is also a geographic region cluster, which improves innovation performance of businesses seeking to gain competitiveness and ability to improve their exportations in the agro-industrial Portuguese sector. The role of the cluster is fundamental to creating a model for knowledge transfer of innovation capacity, interconnecting its institutional, scientific and business associates. This model has to be adapted to the sector and enterprise characteristics, relying in an interconnecting structure which is more or less decentralized according to the mentioned features. Here we present an experience and case study of the Inovcluster ecosystem and its trends and innovation transfer to business value creation, contextualized within the regional strategy for smart specialization. We have shown how, through the establishment of an Inovcluster network, it is possible to integrate the contribution of different research and academic centres, channelled to assist micro-enterprises by innovating within a geographical constraint.

Teresa Paiva, Claudia Domingues, Luıs Pinto de Andrade

18.04.2016.

Original scientific paper

Effects of knife edge angle and speed on peak force and specific energy when cutting vegetables of diverse texture

Cutting tool parameters such as edge-sharpness and speed of cut directly influence the shape of final samples and the required cutting force and specific energy for slicing or cutting operations. Cutting force and specific energy studies on different vegetables help to design the appropriate slicing or cutting devices. Peak cutting force and specific energy requirements for the transverse cutting of nine vegetables, differing in their textural characteristics of rind and flesh, were determined at cutting speeds of 20, 30, 40 mm min−1 and single-cut knife-edge angles of 15, 20 and 25° using a Universal Testing Machine. Low speed (20 mm min−1 ) cutting with a sharper knife-edge angle (15°) required less peak force and specific energy than that of high-speed cutting (40 mm min−1 ) with a wider knife-edge angle (25°). The vegetables with the maximum and minimum variation in the average peak cutting force were aubergine, at 79.05 (for knife speed 20 mm min−1 and edge angle 15°) to 285.1 N (40 mm min−1 and 25°), and cucumber, at 11.61 (20 mm min−1 and 15°) to 21.41 N (40 mm min−1 and 25°), respectively. High speed (40 mm min−1 ), with a large knife-edge angle (25°), required the highest force and specific energy to cut the vegetables, however, low speed (20 mm min−1 ), with a small knife-edge angle (15°), is preferred. Effects of cutting speed and knife-edge angle on peak force and specific energy responses were found significant (p<0.05). Linear or quadratic regressions gave a good fit of these variables.

VISHAL SINGH, Madhusweta Das, Susanta Kumar Das

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