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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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Contents
18.10.2013.
Original scientific paper
Physicochemical characterization of Gozitan Honey
Honey quality is clearly defined in the EU Directive 2001/110/EC, and by Codex Alimentarius (Codex Stan 12-1981) and the International Honey Commission (IHC, 2002). Our investigation aimed to characterize the physicochemical properties of honey produced on a small island, Gozo which is situated near Malta. Ten randomly collected honey samples were analysed for moisture content, pH, free acidity, water insoluble content, hydroxymethylfurfural (HMF) content and total phenolic compounds. Moisture content, pH, free acidity, water insoluble content, and HMF content were within the range specified in standards but the electrical conductivity was generally higher than 0.800 mS cm-1. This may be the result of the relatively high atmospheric and soil salinity on this small island. All the samples analysed were within the 40 mg kg-1 HMF limit, which is an indicator of honey quality. The total phenolic compounds, which represent some of the constituents derived from the nectar and pollen obtained during foraging, ranged between 236.555 and 294.209 GAE kg-1 honey. Principal Component Analysis showed the properties of polyfloral honey samples obtained from the southern part of the island to be different from those obtained from the northern part.
Everaldo Attard, Joseph Mizzi
18.04.2013.
Original scientific paper
Effect of antioxidant and optimal antimicrobial mixtures of carvacrol, grape seed extract and chitosan on different spoilage microorganisms and their application as coatings on different food matrices
There is growing interest in the use of natural agents with antimicrobial (AM) and antioxidant (AOX) properties. Optimization of the AM capacity for mixtures containing carvacrol, grape seed extract (GSE) and chitosan, against gram-negative (Pseudomonas aeruginosa), gram-positive bacteria (Staphylococcus aureus, Listeria innocua and Enterococcus faecalis) and yeast (Saccharomyces cerevisiae) at 106 cfu mL-1 was studied. To observe the synergistic or antagonistic effect and find optimal combinations between the three agents, a simplex centroid mixture design was run for each microorganism, combining carvacrol (0-300 ppm, X1), GSE (0-2000 ppm, X2) and chitosan (0-2% w/v, X3). Results of the response surface analysis showed several synergistic effects for all microorganisms. Combinations of 60 ppm-400 ppm-1.2% w/v (carvacrol-GSE-chitosan; optimal AM combination 1, OAMC-1); 9.6 ppm-684 ppm-1.25% w/v (OAMC-2); 90 ppm-160 ppm-1.24% w/v (OAMC-3) were found to be the optimal mixtures for all microorganisms. Radical scavenging activity (RSA) of the same agents was then compared with a standard AOX (butylated hydroxytoluene; BHT) at different concentrations (25, 50 and 100 ppm; as well as the optimal AM concentrations) by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. RSA increased in the following order: chitosan< carvacrol< BHT< GSE and for the OAMC: OAMC-2< OAMC-1< OAMC-3. The best RSA (OAMC-3) was applied as a coating in two different food matrices (strawberries and salmon). For strawberries, P. aeruginosa was more sensitive to the action of OAMC-3 than S. cerevisiae. For salmon, S. aureus was more resistant to the action of OAMC-3 than E. faecalis and L. innocua.
Javiera F. Rubilar, Rui M.S. Cruz, Igor Khmelinskii, Margarida Vieira
18.04.2013.
Original scientific paper
Effect of Biopreservatives on Storage Life of Papaya (Carica papaya L.)
In this experiment the effect on post-harvest preservation of papaya (Carica papaya L.) fruit coated with either Aloe gel (AG; 100%) or papaya leaf extract with Aloe gel (PLEAG; 1:1) was studied. To evaluate the role of coating on ripening behavior and quality of papaya the uncoated and coated fruits were stored and ripened at room temperature (25 °C-29 °C) and 82-84% relative humidity. Physico-chemical properties were analyzed at 4 day intervals during the storage period. The incidence of disease attack was also visually observed. The overall results showed the superiority of AG and PLEAG coating in lengthening the shelf-life of papaya fruit compared to controls which showed significant decay from 6th day onward and complete decay within 12 days of storage. The AG and PLEAG coated fruits maintained their shelf life for 12 days and decayed at 16th day. The coated fruits also maintained their color, flavor and firmness up to 12 days of storage. An increase in ascorbic acid content (120.2 mg/100 g) was also found in coated fruits in contrast to the control (59 mg/100 g). Only 27% disease incidence was observed in AG and 13% in PLEAG coated fruits as compared to control (100%) during the storage period. The results of this study show that both AG and PLEAG coatings have excellent potential to be used on fresh produce to maintain quality and extend shelf-life.
Fatema Brishti, Jawadul Misir, Ayesha Sarker
18.10.2013.
Original scientific paper
The AgroParisTech “Social Openings” mission
Underprivileged secondary school and college students tend to demonstrate limited ambitions with regards to further education and acquiring superior qualifications. In a partnership with higher education schools, such as AgroParisTech, encounters have been organised between high school students and higher education students acting as volunteering mentors.The aim is to present the high school students with the opportunity to explore new opportunities as well as to provide them with information about high profile careers and higher level training through various activities led by the higher education students, as well as through meetings, visits, weekends organised around a specific theme. Examples of such initiatives show what benefits both the high school and higher education students can derive from them.
Annie Baroiller, Elisabeth Dumoulin
18.10.2012.
Original scientific paper
Effect of drying techniques on the retention of antioxidant activities of Saskatoon berries
The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P<0.05. DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P<0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P<0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P<0.05.
Pranabendu Mitra, Venkatesh Meda, Rick Green
18.04.2013.
Original scientific paper
The impact of cold chain temperature abuses on the quality of frozen strawberries (Fragaria ×ananassa)
The quality of frozen foods can be negatively affected if improper storage and distribution temperatures are allowed. The objective of this study was to investigate the effect of freeze-thaw cycles, which may occur in the cold chain, on colour (Lab, Total Colour Differences (TCD), chroma and hue angle) and vitamin C (ascorbic and dehydroascorbic acids) content of frozen strawberries (Fragaria ×ananassa, Duschesne, cv. Selva). A plan of temperature abuses (TAs) was established, based on a real situation, and applied to frozen strawberries during a four month frozen storage period. The results showed that the lightness (L) was the only parameter that was not significantly affected by range of TAs studied. The colour showed some variation on the parameters a, b, TCD, chroma and hue angle. During TAs, ascorbic acid decreased about 75% and dehydroascorbic acid increased 73%. The non-abused strawberry samples showed better overall appearance than the abused samples. This work contributes to an understanding of the quality changes of frozen strawberries that might occur during frozen storage and cold chain distribution.
Rui Cruz, Margarida Vieira, Cristina Silva
18.10.2013.
Original scientific paper
Quality and safety of camel milk along the value chain in Eastern Ethiopia
The safety of camel milk was assessed along the value chain in Erer, eastern Ethiopia. A total of 24 camel milk samples were aseptically collected from producers in Erer (n=12), and wholesalers and retailers (n=12) along the chain. Milk quality parameters were analyzed following standard procedures. The mean (±SD) total bacteria (TBC), Enterobacteriaceae (EC), coliform (CC), spore-forming bacteria (SFBC) and yeast and mould (YMC) counts of the milk samples analyzed were 5.2 ± 1.90, 3.2 ± 2.30, 2.9 ± 2.27, 2.1 ± 2.41 and 2.7 ± 1.61 log10 cfu mL-1, respectively. The TBC, EC, CC and SFBC of milk samples obtained from retailers in the final marketing sites were significantly higher (P < 0.05) than those obtained from producers and wholesalers in Erer. Salmonella spp. was detected in milk samples collected from all sites. Other microorganisms isolated from camel milk samples include Staphylococcus aureus (16.2%), Entrobacter spp. (14.9%), Streptococcus spp. (13.5%),Escherichia coli (8.1%), Acinetobacter spp. (7.4%), Staphylococcus epidermidis (6.8%), Klebsiella spp. (6.1%), Bacillus spp. (5.4%), Corynebacterium spp. (5.4%), Micrococcus spp. (4.7%), Lactobacillus spp. (4.1%), Listeria spp. (4.1%), Pseudomonas spp. (2%) and Shigella spp. (1.4% ). The quality of camel milk produced in the study area was generally poor and microbial contamination of camel milk occurs along the value chain while it is transported from the production site to the market. This calls for strict hygienic measures along the entire value chain in order to improve the quality and safety of camel milk produced in the area evaluated.
Mulugojjam Adugna, Eyassu Seifu, Ameha Kebeded, Reiner Doluschitz
18.10.2012.
Original scientific 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
18.04.2012.
Original scientific 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 Lazarides
18.10.2012.
Original scientific paper
Drying kinetics and quality aspects during heat pump drying of onion (Allium cepa L.)
A prototype heat pump dryer has been developed for drying of fruits and vegetables at low temperature and relative humidity to maintain the quality of dried product. Onions, of Nasik red variety were peeled, trimmed and sliced to 2 mm thickness. The onion slices were dried in the heat pump dryer at 35ºC (32 % R.H.), 40ºC (26 % R.H.), 45ºC (19 % R.H.) and 50ºC (15 % R.H.). Samples were also dried in a hot air dryer at 50ºC (52 % R.H.) for comparison. The drying rate increased with increase in drying air temperature, associated with reduced R.H., in the heat pump dryer. Drying took place mainly under the falling rate period. The Page equation, resulting in a higher coefficient of determination and lower root mean square error, better described the thin-layer drying of onion slices than the Henderson and Pabis equation. Heat pump drying took less drying time of 360 min and yielded better quality dried product, with higher retention of ascorbic acid and pyruvic acid and lower colour change, as compared to a hot air dryer at the same drying air temperature of 50ºC.
Nihar Sahoo, Uma Sankar Pal, Sanjaya Kumar Dash, M.D. K. Khan