Advances in Food Science and Engineering

5

Authors: Rui Xu, Xi-yan Zhao, Shuo Guo, Qi Yang

As a glycoprotein, lactoferrin has many biological actions, among which the antibacterial activity is one of the most important effects studied. Bovine lactoferricin (Lfcin B) is a cationic peptide that possesses potent in vitro and in vivo antibacterial activity, and might affect the expression of DNA Adenine Methyltransferase (DAM). In the present study, the artificially synthesized Lfcin B and Lfcin B derived peptide (Cys 19 residue in Lfcin B was replaced by Ala) were added in Escherichia coli, and we determined the messenger ribonucleic acid and protein expression of DAM in Escherichia coli after incubated with Lfcin B by real-time quantitative reverse transcription PCR and Western blot analysis. The results of real–time quantitative reverse transcription PCR showed that DAM expression was reduced after treatment with Lfcin B. The results of western blot analysis showed that the expression of DAM protein was down-modulated by Lfcin B.

10

Authors: K. Kemashalini, B.D. Rohitha Prasantha, K.A.K.L. Chandrasiri

Physico-chemical and pasting properties of high-amylose rice flour (Bg 360) and low-amylose rice flour (At 405) were tested in this study. A modified visco-amylograph method was used to test the pasting behavior of rice flours. Amylose content, damaged starch, swelling power, water absorption capacity and sedimentation volume showed a significant difference between the two rice flours. The At 405 rice flour contained significantly higher damage starch content (%), swelling power (g/g), water absorption capacity (%) and low crude fat content (%) compare to Bg 360. The amylose content of rice flour showed a strong but negative correlation with damaged starch, swelling power and water absorption capacity of rice flour. Damaged starch showed a significant positive correlation with swelling power and water absorption capacity. Despite the breakdown of the viscosity (mPa s) did not show significant differences, setback viscosity, pasting temperature and time of high-amylose flour showed significantly higher values than low-amylose flour.

11

Authors: Kouamé Adam Camille, Abodo Jacko Rhedoor, Coulibaly Aissatou, N’dri Yao Denis, Pereko Kingsley Kwadwo Asare, Amani N’guessan Georges

The rapid increase in diabetes incidence in Côte d’Ivoire indicates the need to evaluate the nutritional profile of foods. In this study, we performed a nutritional characterization and glycemic index/load (GI/GL) of pounded plantain, which is the predominant mode of banana consumption. Five groups of 13 apparently healthy subjects consumed in random order 5 experimental products variants and twice a glucose solution. Proximate composition was conducted by AOAC standard methods. The GI was obtained following ISO/FDI 26642:2010 protocol and the GL was calculated from test food’s GI, considering the amount of available carbohydrate in the traditional portion size. Moisture of samples ranged from 55.8–70.9g/100g. Based on dry weight per 100 gram, the samples had 0.2-0.8g ash, 0.3-1.3g lipids, 3.5-10.5g protein, 1.8-1.9g crude fibre, 86.8-94.1g carbohydrates and 398.4-403.5kcal for energy. Excepted pounded plantain from agnrin variety at “green” stage of ripeness (GI 40), the corresponding GI values were high (GI 75-84). The GL values of the foods tested were also considered high, varying from 60 to 144. Data showed that pounded plantain is potentially a source of high GI/GL carbohydrate.

17

Authors: Warinporn Klunklin, Geoffrey Savage

Biscuits are excellent snacks with a long shelf life. However, they are also high-energy foods so there is a great need to improve their nutrient value. Many substitutions of composite flours for wheat flour have been studied in order to reduce their potential negative impact on human health. Whole purple rice flour is a novel flour with high antioxidant contents and dietary fiber. However, the partial replacement of wheat flour with purple rice flour can affect the physicochemical properties and consumer preferences of biscuits. Therefore, producing a new product to meet consumer demands presents many challenges. Lipid oxidation is always a problem during extended storage. Inhibition of lipid oxidation in biscuits leading to rancidity and loss of nutritional value is also an important consideration for these biscuits. There is a high demand to use natural antioxidants in foods to enhance the shelf life of biscuits. Hence the scope of replacing wheat flour with purple rice flour in biscuit production needs further study.

9

Authors: Ivan Švec, Marie Hrušková

Three different addition levels of commercial fonio flour (2.5, 5.0, 10.0%) were mixed with wheat flour to explore flour pasting, dough rheological behaviour and bread quality. During farinograph test, fonio flour addition clearly shortened wheat dough stability (from 12.0 up to 3.5 min). Extensigraph data were influenced equivocally. Viscosity profiles determined by using of Amylograph and Rapid Visco Analyser, corresponded together (peak viscosities 2263 (control), 2348, 2367, 2381 mPa∙s). During fermentograph, maturograph and oven-spring tests, composite dough variants exhibited higher dough volumes (+20% in average). Bread volume has risen by 2.5% fonio flour dosage only (from 337 to 402 ml/100 g); specific volumes of more enhanced variants were comparable to control. Crumb penetration corresponded to specific bread volume, rising from 12.6 mm to 22.3 mm. Fonio wholemeal did not affected bread sensory profiles. Principal component analysis pointed to higher baking potential of wheat-fonio composite 95:5.

6

Authors: P. R. Davara, N. C. Thumar, J. J. Limbasiya, H. V. Agravat, V. P. Sangani

Wheat is the most important mainly due to its use in the flour production. An experiment was conducted to study the feasibility of evaporative water cooled grinding for wheat flour production. Wheat was mixed with water (0%, 3%, 6% and 9% w/w) and grinded immediately using domestic hammer mill before the surface water penetrated into the grain. The different grinding characteristics were studied for the grinding operation. This process resulted in cooling since the evaporating particles carried away the heat generated inside the grinding mill resulting in decrease of the temperature of the system. The temperature during grinding was found to be decreased by 11°C under for the sample wetted with 9% (w/w) of water as compared to conventional grinding. No sieve clogging was observed during evaporative water cooled grinding. Grinding time was observed to be increased by 155 sec for the evaporative water cooled ground sample. This study revealed that the evaporative water cooled grinding method can be effectively used for avoiding the rise in temperature during grinding in order to preserve the quality of wheat.

8

Authors: Olusegun A. Olaoye, Stella C. Ubbor, Iniobong G. Lawrence

This study examined the effect of different packaging materials on some quality indices of a Nigerian stick meat (tsire) during spontaneous storage at 30oC for four days. The packaging materials included those normally used for wrapping of the product during sales to consumers, and they were ‘common paper’, ‘dry banana leaves’, ‘cellophane paper’ and ‘aluminium paper’. Analysis during storage showed that the tsire samples stored in cellophane paper had the highest concentration of lactic acid (14g/kg), while 10g/kg was recorded as the lowest concentration for samples stored in common paper. There was reduction in pH of the tsire samples stored in the different packaging materials during storage from 6.9 on day 1 to 5.9 on day 4, although no significant difference (p>0.05) was recorded between samples. Thiobarbituric acid (TBA; mg malonaldehyde/kg sample) ranged from 0.38 and 040 on day 1 among the different samples, and the values increased during storage to a range of 0.74 to 0.81 on day 4; however, the values did not differ significantly (p>0.05) among samples. Principal component analysis (PCA) of the volatiles associated with the tsire samples during storage indicated that known spoilage compounds, including nonanal and heptanal, were detected in all samples, especially on days 3 and 4. In conclusion, the different packaging materials recorded no significant effect (p>0.05) on the tsire samples during storage. However, TBA values and volatiles recorded suggested likely presence of spoilage in the samples during storage.

10

Authors: Fernanda Rosa Assis, Rui Manuel Santos Costa de Morais, Alcina Maria Miranda Bernardo de Morais

The effects of the pre-osmotic treatment on the mass transfer kinetics of the freeze-drying (FD) and on the water activity (aw) and the quality – colour, total phenolic content, antioxidant activity – of apple cubes were studied. The fit of the moisture content was carried out using several mathematical models. The comparison among FD, microwave drying (MWD) and hot air drying (HAD) of osmotically treated apple cubes was also performed according to the drying rate and the aw. The apple cubes were osmotically treated with 60ºBrix sucrose or sorbitol solutions at 60ºC, then frozen and freeze-dried. The FD reduced significantly the moisture content from 6.259, 1.086 and 1.031 to 0.138, 0.099 and 0.074 kgwater.kgdry matter-1 for the control and the samples osmotically pre-treated with sucrose and sorbitol, respectively. The modified Page’s model presented the highest precision of parameter estimates. The FD of samples osmotically pre-treated with the sucrose solution resulted in a higher drying rate than the others samples. The highest reduction in aw was observed in the fresh samples. After FD, the total phenolic content and the antioxidant activity of the osmotically pre-treated samples decreased around 80%, in comparison with the fresh apple, this reduction being due to the osmotic pre-treatment. The freeze-dried control samples achieved a lower aw in comparison with HAD and MWD. However, FD presented a lower drying rate.

5

Authors: Ayuba L., Agboire S., Gana A.K., Ishaq M., Aliyu U., Affiniki G., Manjang J. I.

The potential of using castor oil as an antibacterial agent was investigated on three species of bacteria chiefly responsible for throat, skin and enteric infections. Staphylococcus aureus was used as the test organism for skin bacteria, the throat bacteria used was Streptococcus viridans, while for enteric bacteria, Shigella dysenteriae was used. Castor oil was extracted by cold pressing of seed kernels. The extract obtained was assayed for antimicrobial activity on the in-vitro growth of test organism using direct inoculation, paper disc method. These were soaked in the castor oil for 1 hour. The soaked discs were then placed on prepared plates each containing the test bacteria, the antimicrobial effect of the castor oil was observed by measuring the zone of inhibition of the agent against the test bacteria. The result showed that castor oil is highly effective against all the bacteria species tested; the zone of inhibition measured, showed that Staphylococcus aureus is more susceptible to the oil than the other bacteria with a range of 11-13mm while Streptococcus viridans had a range of 8-10mm and the least was Shigella dysenteriae which had a range of 3-6mm. The result obtained implies that castor oil can be used in the control of wounds, skin infections, throat infections and in the treatment of stomach unrest caused by these bacteria species.

6

Authors: Samira Nair, Nebia Bouzidi Maghraoui

Honey is a nutritious product that is produced by honey bees. Its composition depends highly on the type of flowers utilised by the bee as well as the climatic conditions. This study was intended to evaluate the quality parameters of ten honey samples, from various regions in NorthWest of Algeria. The physicochemical property of the honeys [moisture, electrical conductivity, hydroxymethylfurfural, pH, acidity (free, total and lactone), reducing sugars, apparent sucrose, insoluble material, ash, and diastase activity] was determined. The moisture shows values of 14.21±0.18 % and 16.59±0.12%. The water insoluble material content ranged between 0.01 ± 0.03 to 0.67 ± 0.07%. The reducing sugars were between 66.3 ± 0.37 and 88 ± 0.23 %, mean percentages of apparent sucrose were 6.54 ± 0.23%. Honey samples showed an appropriate diastase number with an average of 12.35 ± 0.24, and their HMF (hydroxymethylfurfural) content ranging from 5.65 ±0.37 to 37.42 ± 0.55 mg/kg, Conductivity values ranged from 10 ± 0.54 to 606 ± 2.45 µS/cm. The ash content ranged from 0.019 ± 0.01% to 0.37 ± 0.05%. All honeys were acidic, having a pH in the range 3.7 ± 0.03– 4.78 ± 0.05. The average values for free acidity in samples were between 10 ± 0.22 and 25 ± 0.5 meq/kg. Lactonic acidity ranges were from 2 ± 0.15 to 5 ± 0.15 meq/kg. Total acidity ranged from 12 ± 0.37 to 30 ± 0.65 meq/kg. All the samples were found to meet all major national and international honey specifications.

11

Authors: Fernanda Rosa Assis, Rui Manuel Santos Costa de Morais, Alcina Maria Miranda Bernardo de Morais

The aim of the present work was to study the effects of the osmotic dehydration (OD) on the mass transfer kinetics of the microwave drying (MWD) and some quality parameters of apple cubes. The fit of several mathematical models was tested to describe the drying. A comparison between MWD and hot air drying (HAD) was performed. Apple cubes were osmotically treated with 60ºBrix sucrose or sorbitol solutions at 60ºC and dried at a microwave power between 160 and 850 W. Overall, the increase of the microwave power from 160 to 500 W resulted in an increase of the water loss rate, shown by the A parameter of modified Page’s model, of 123 and 155% for samples osmotically dehydrated with sucrose and sorbitol solutions, respectively. The OD tends to increase the drying rate, but the osmotic agent used did not have any effect. The modified Page's model described well the drying kinetics and MWD was faster than HAD. The water activity of the osmotically dehydrated product was reduced to below 0.4 after MWD at 500 W. The MWD of control samples resulted in a loss of 39% and 28% of the total phenolic content and the antioxidant activity, respectively. For osmotically dehydrated samples, a loss of around 75% was observed for both these quality parameters after the osmotic treatment.