Current issue
Volume 13, Issue 2, 2024
Online ISSN: 2182-1054
Volume 13 , Issue 2, (2024)
Published: 18.10.2024.
Open Access
All issues
Contents
18.04.2014.
Original scientific paper
Effect of protease inhibitors on thermal gelation of squid (Illex argentinus). mantle paste
The characteristics of the thermal gelation of squid mantle paste and the effect of protease inhibitors on them were investigated. Pastes in the absence and presence the protease inhibitors, ethylendiaminetetracetic acid (EDTA) and phenylmethylsulfonyl fluoride (PMSF), were formulated. Pastes were made by the respective one or two step thermal treatments: direct heating at 85°C for 20 min and preincubation at 27 or 40 °C for 3 or 2 hours, followed by heating at 85 °C for 20 min. The gel strength, water holding capacity (WHC) and whiteness of gelled pastes were analyzed. The tricloroacetic acid (TCA) soluble peptides in homogenate of the muscle were determined. Gel strength decreased when heating was made in two steps. EDTA and PMSF were effective in avoiding that decrease when pre-incubation was made at 40 °C. Maximum gel strength was observed for the gels in presence of EDTA, giving values of 255 and 219 g x cm for the samples made by direct heating and pre-incubated at 40 °C respectively. TCA soluble peptides increased between 20 and 60 °C, with maximum values reached at 30 and 60 °C. No significant differences (p>0.05) were observed in gel whiteness, neither with the thermal treatment nor with the inhibitors. The WHC was higher (p<0.05) in the gelated paste formulated with EDTA. These results show a good gelation capacity of I argentinus pastes and improvements with protease inhibitors.
Maria Elida Paredi, Emilio Aldo Manca, Marcos Crupkin
18.10.2014.
Original scientific paper
Functional properties of proteins isolated from industrially produced sunflower meal
Protein isolate 1 (PI1) and protein isolate 2 (PI2) were prepared from industrially produced sunflower meal by using isoelectric and ethanol precipitation respectively. The water absorption capacity of PI1 was 6 times higher than that of PI2 and was significantly reduced by the presence of 0.03 M and 0.25 M NaCl. Oil absorption capacity of both protein isolates was not influenced by NaCl supplementation. Foam capacity of PI1 and PI2 was pH-dependent. While the foam capacity of both isolates was improved by either 0.03 M or 0.25 M NaCl, the foam stability was negatively influenced by the addition of NaCl at all pH values with except for pH 4. Emulsifying activity of PI1 and PI2 was lowest at pH 4. The emulsions exhibited relatively high stability (> 90%) under all studied conditions. Knowledge of the influence of pH and boundary concentrations of NaCl on the functionality of sunflower meal protein isolates could be beneficial for their future potential application in food industry.
Petia Ivanova, Vesela Chalova, Lidia Koleva
18.10.2014.
Original scientific paper
Evaluation of cookies produced from blends of wheat, cassava and cowpea flours
Cassava (Manihot esculenta Crantz) and cowpea (Vigna unguiculata L. Walp) were processed into flours and used to substitute wheat flour for preparation of cookies. The chemical, including proximate composition and anti-nutritional factors, and functional and pasting properties of the blends were determined. Cookies were produced from the blends with 100% wheat flour as a control. The antinutritional factors, physical properties and organoleptic attributes of the cookies were evaluated. An increase in the level of cassava flour substitution resulted in a decrease in the protein content of the composite flour. However, addition of cowpea flour resulted in an increase in the protein content. There were significant (p<0.05) reductions in the studied anti-nutritional factors after baking. Cookies from composite flours were not significantly (p>0.05) different from the control in overall acceptability. This indicates the feasibility of producing nutritious cookies with desirable organoleptic qualities from cassava, wheat and cowpea composite flour.
Abiodun Olapade, Adeyemo Abimbola Mary
18.10.2014.
Original scientific paper
Characterization of potent odorant compounds in Turkish olive oils by GC-MS-olfactometric techniques
The purpose of this study was to determine the most powerful aroma-active compounds of olive oils obtained from Ayvalik (AYV), Gemlik (GEM) and Memecik (MEM) cultivars harvested in 2011, using gas chromatography-mass spectrometry-olfactometry (GC-MS-O). Simultaneous distillation and extraction (SDE) with dichloromethane was used for extraction of volatile components. The aromaactive compounds of olive oils were evaluated by aroma extract dilution analysis (AEDA). A total of 14, 12 and 12 aroma-active compounds within the range of ≥64–1024 flavor dilution (FD) factors were detected in aromatic extracts of olive oils obtained from AYV, GEM and MEM cvs., respectively. The compounds having the highest FD factor (1024) were (Z)-3-hexenol (cut grass, herbal) and βsesquiphellandrene (floral) for AYV oil and (Z)-3-hexenyl acetate (fruity) for MEM oil. Among these compounds, terpenes were the overwhelmingly largest aroma-active components followed by aldehydes.
Songul Kesen, Hasim Kelebek, Serkan Selli
18.10.2014.
Original scientific paper
Fermentation and antimicrobial characteristics of Lactobacillus plantarum and Candida tropicalis from Nigerian fermented maize (akamu)
This study investigated the ability of Lactobacillus plantarum strains (NGL5 and NGL7) and Candida tropicalis (NGY1) previously identified from akamu-a Nigerian fermented maize food with probiotic L. plantarum LpTx and Saccharomyces boulardii SB20 to ferment ground maize slurries based on pH, acidity, microbial biomass, levels of sugars and organic acids, and their antimicrobial activity against Salmonella enterica serovar Enteritidis NCTC 5188, Escherichia coli NCTC 11560, Bacillus cereus NCIMB 11925, Staphylococcus aureus NCTC 3750 and Listeria monocytogenes NCTC 7973 using an agar spot assay. L. plantarum strains either as single or mixed starter cultures with the yeasts had growth rates ≥0.15 h−1 , with pH significantly (p≤0.05) decreased to ≤3.93 after 12 h and then to ≤3.52 after 72 h and lactic acid >84 mmol L−1 . The yeasts had growth rates ≥0.18 h−1 but pH was ≥4.57 with lactic acid levels ≤20.23 mmol L−1 after 72 h in the single culture fermentation. There was no inhibition in modified MRS agar: 0.2% glucose and 0.2% glucose without Tween 80. Inhibition halos in MRS agar varied from 10.6 to 23.9 mm. S. bourladii was more inhibitory towards L. monocytogenes (8.6 mm) and B. cereus (5.4 mm ) than was C. tropicalis (1.1 and 3.3 mm for L. monocytogenes NCTC 7973 and B. cereus NCIMB 11925 respectively) (0.9 mm) in malt extract agar. This study showed that C. tropicalis was less inhibitory to the pathogens while antimicrobial activities of the L. plantarum strains were mainly due to acidity and the L. plantarum strains either as single or mixed cultures with the yeasts demonstrated strong fermentation ability, with significant decrease in pH which is vital in the choice of starter for product safety
Patience C. Obinna-Echem, Victor Kuri, Jane Beal
18.04.2014.
Original scientific paper
Effects of Lactic Acid Fermentation on the Retention of Β-Carotene Content in Orange Fleshed Sweet Potatoes
This study aimed to establish the effects of lactic fermentation on the levels of β-carotene in selected orange fleshed sweet potato (OFSP) varieties from Kenya. Furthermore,it sought to demonstrate fermentation as a potential process for making new products from sweet potato with enhanced nutraceutical attributes. The varieties (Zapallo, Nyathiodiewo and SPK004/06) were fermented with Lactobacillus plantarum MTCC 1407 at 25 ± 2°C for 48 h and kept for 28 days to make lacto-pickles. During fermentation both analytical [pH, titratable acidity (TA), lactic acid (LA), starch, total sugar, reducing sugar (g/kg roots), texture (N/m2), β-carotene (mg/kg roots)] and sensory (texture, taste, flavour and after taste) attributes of sweet potato lacto-juice were evaluated. Process conditions were optimized by varying brine levels, with fermentation time. A UV-visible spectrophotometer was used to identify and quantify β-carotene. Any significant variations (p < 0.05) in analytical attributes between the fermented and unfermented samples (pH, LA, TA and β-carotene concentration) of lacto-pickles, prepared from the potato roots, were assessed. The study reported a final composition of 156.49mg/kg, 0.53mg/kg, 0.3N/m2, 1.3g/kg, 5.86g/kg, 0.5g/kg and 5.86g/kg for β-carotene, Ascorbic acid, texture; Starch, total sugars, LA and TA respectively, and a pH of 3.27. The fermented products were subjected to flavour profiling by a panel. The product sensory scores were 1.5 to 2.5 on a 5 point hedonic scale, ranging from dislike slightly to like much. The products with brine levels at 4 and 6% were most preferred. The retention of β-carotene was 93.97%. This demonstrated lactic acid fermentation as a better method for processing OFSP as the main nutritional attributes are retained. The final product was resistant to spoilage microorganisms after 28 days of fermentation. Further preservation could be obtained by addition of sodium metabisulphite. In conclusion, Lactic acid fermentation using L. plantarum is a novel method of producing Lacto pickles from Zapallo OFSP, with 93.97% β-carotene retention and adequate shelf life.
Benard O. Oloo, A. A. Shitandi, S. Mahungu, J. B. Malinga, Rose B. Ogata
18.10.2014.
Original scientific paper
Determination of the antioxidant capacity, total phenolic and flavonoid contents of seeds from three commercial varieties of culinary dates
Date seeds are a major waste product of the date industry that could offer potentially valuable material for the production of useful food ingredients. The aim of the present study was to investigate the seeds of three date varieties of the UK market (Deglet Nour, Khouat Allig, and Zahidi) for their proximate composition, total phenolic (TPC), total flavonoid (TFC) contents and total antioxidant capacity (TAC) with a view to their eventual industrial application. Carbohydrates were present in the highest concentrations varying between 74.13 and 76.54 g 100 g-1 of date seed powder (DSP) on dry weight (DW) basis, followed in descending order by fats (7.64-8.84 g 100 g-1) and proteins (4.35-5.51 g 100 g-1). Potassium was found in high amounts with values ranging between 280.55 and 293.13 mg 100 g-1. The majority of the total phenolic content (2058-2984 mg GAE 100 g-1) was assumed to be composed of flavonoids (1271-1932 mg CAE 100 g-1). These families of dietary phenolics may be the major ones responsible for the high antioxidant capacity reported in date seeds, which varied from 12540 and 27699 µmol TE 100 g-1. These results suggest that date seeds can be considered a potential raw material for natural, active ingredients for food applications as well as an unexplored source of novel nutraceuticals and dietary supplements.
Jacopo Mistrello, Sameera Dewundara Sirisena, Abdollah Ghavami, Richard James Marshall, Suresh Krishnamoorthy
18.04.2014.
Original scientific paper
Effect of Buckwheat Processing Products on Dough and Bread Quality Made from Whole-Wheat Flour
The paper gives a brief overview of the current nutritional status of the Ukrainian population and describes useful buckwheat properties. The objective of the paper is to study the effect of buckwheat processing products (flour and flakes) on the technological process and quality of bread made from whole-wheat flour. This paper describes and analyzes research data on the rheological properties of dough samples which were determined by farinograph and amylograph. Investigation of structural and mechanical properties of dough showed an increase in water-absorbing capacity in all samples when adding buckwheat products. Moreover, dough made with buckwheat flakes has a lower value of mixing tolerance index (by 47 %) than dough made from buckwheat flour, and a higher valorimetric value (by 20 %). Determination of dough properties by amylogram has shown that a sample containing buckwheat flakes has a higher maximum viscosity than a sample containing buckwheat flour. Determination of the gas-production and gas-retention capacity of dough is also presented, along with an analysis of the quality of finished products based on the results of laboratory baking tests. The samples of bread supplemented with buckwheat flakes have better shape stability (by 21 %), specific volume (by 12 %) and porosity (by 11 %) than bread made from buckwheat flour. The organoleptic evaluation of finished product quality has shown that bread supplemented with buckwheat flakes has a more fluffy-texture, elastic crumb and uniform porosity than bread made from buckwheat flour. Buckwheat flakes proved to have a better effect on parameters of the technological process and quality of bread when compared with buckwheat flour.
Anastasiya Semenova, Anastasiya Semenova, Jelyzaveta Smirnova, Larisa Mykhonik
18.04.2014.
Original scientific paper
Vegetable milks and their fermented derivative products
The so-called vegetable milks are in the spotlight thanks to their lactose-free, animal protein-free and cholesterol-free features which fit well with the current demand for healthy food products. Nevertheless, and with the exception of soya, little information is available about these types of milks and their derivatives. The aims of this review, therefore, are to: highlight the main nutritional benefits of the nut and cereal vegetable milks available on the market, fermented or not; describe the basic processing steps involved in their manufacturing process; and analyze the major problems affecting their overall quality, together with the current feasible solutions. On the basis of the information gathered, vegetable milks and their derivatives have excellent nutritional properties which provide them a high potential and positive market expectation. Nevertheless, optimal processing conditions for each raw material or the application of new technologies have to be researched in order to improve the quality of the products. Hence, further studies need to be developed to ensure the physical stability of the products throughout their whole shelf-life. These studies would also allow for a reduction in the amount of additives (hydrocolloids and/or emulsifiers) and thus reduce the cost of the products. In the particular case of fermented products, the use of starters which are able to both improve the quality (by synthesizing enhanced flavors and providing optimal textures) and exert health benefits for consumers (i.e. probiotics) is the main challenge to be faced in future studies.
Neus Bernat, Maite Cháfer, Amparo Chiralt, Chelo González-Martínez
01.12.2013.
Professional paper
Effect of pre-treatments on solar drying kinetics of red seedless grapes (cv. Monukka)
Inês Nunes Ramos, Teresa R.S. Brandão, Cristina L.M. Silva