Anthocyanin-rich sweet potato lacto-pickle: production, nutritional and proximate composition

Anthocyanin pigment-rich sweet potato (SP) cubes were pickled by lactic fermentation by brining the cut and blanched cubes in common salt (NaCl, 2–10%) solution. They were then inoculated with a strain of Lactobacillus plantarum (MTCC 1407) and incubated for 28 days. Treatment with 8–10% brine solution was found to be organoleptically most acceptable. The final product with 8% and 10% brine solutions had a pH (2.5–2.8), titratable acidity (TA) (1.5–1.7 g kg⁻¹), lactic acid (LA) (1.0–1.3 g kg⁻¹), starch (56–58 g kg⁻¹) and anthocyanin content (390 mg kg⁻¹) on fresh weight basis. Sensory evaluation rated the anthocyanin-rich SP lacto-pickle acceptable based on texture, taste, aroma, flavour and after taste. Principal component analyses reduced the eleven original analytical and proximate variables (pH, TA, LA, starch, total sugar, anthocyanin, organic mater, ash, fat, protein and calories) to three independent components (factors), which accounted for 91% of the total variations.     

Enzymatic Production of High-Protein Amaranth Flour and Carbohydrate Rich Fraction

The basic conditions of an enzymatic process to produce high-protein amaranth flour (HPAF) and carbohydrate rich fraction (CRF) from raw flour were determined. Commercial preparations of α-amylase and glucoamylase were used. Conditions for both enzymes were: 20% (w/v) slurries of gelatinized whole flour and 0.10% (v/w) enzyme; for amylase, pH 6.5, 70°C and 30 min liquefaction time; for glucoamylase, pH 4.5, 60°C and 60 min. The yield of HPAF was 38–39%. HPAF from both enzymes had 26–28% protein, 10–16% fat and 40–52% starch. Protein digestibility (76%) and reactive lysine (6.6–7.1 g/100g protein) of HPAF were comparable to raw flour. CRF had a 17–21 dextrose equivalent.     

Effects of trace element supplementation on milk yield and composition in camels

Objective of the study was to determine milk yield and quality (fat, protein, mineral content) of camels reared in north-east Africa, supplemented with trace elements for the first nine months of lactation. Twelve multiparous lactating camels were divided into two groups: control and treated (trace element supplemented). Addition of trace elements did not affect milk production and milk fat and protein content (respectively 3.09 vs. 3.51 kg d⁻¹; 2.86 vs. 2.56%; 3.31 vs. 3.19%, treatment vs. control). Calcium and zinc contents of milk were significantly higher in treated animals (1.20 vs. 0.94 g L⁻¹ and 3.16 vs. 2.52 mg L⁻¹; P<0.01). Mineral status of lactating camels and of their calves was assessed by analysis of plasma. Camel control diet was deficient in copper and supplementation did not allow reaching, neither in milk nor in plasma, the threshold values. Results suggest that oral trace element supplementation could increase zinc excretion in camels’ milk, despite the low levels of zinc in plasma.     

Cloud point extraction and spectrofluorimetric determination of aluminium and zinc in foodstuffs and water samples

Cloud point methodology was successfully used for the extraction of trace amounts of aluminium and zinc as a prior step to their determination by spectrofluorimetry. Aluminium and zinc react with 8-hydroxyquinoline in a surfactant solution yielding a hydrophobic complex, which then is entrapped in surfactant micelles. Optimization was performed of the variables affecting complexation and phase separation. Under the experimental conditions used, preconcentration of 25 ml of sample in the presence of 0.12% (v/v) Triton X-114 permitted the detection of 0.79 μg l⁻¹ of aluminium and 1.2 μg l⁻¹ of zinc, respectively. The relative standard deviation for five replicate determinations of aluminium and zinc at 40 and 100 μg l⁻¹ concentration level, were 2.72 and 2.1%, respectively. Good recoveries in the range of 95–104% were obtained for spiked samples. The proposed method was applied to the determination of aluminium and zinc in different samples.     

赤水晒醋中增黏微生物的分离鉴定及特性研究

从变质赤水晒醋中分离筛选出导致黏度增加的菌株N3、N5、N7和N11,检测其生理生化特征,并进行16S rDNA基因序列分析及生长特性研究。结果表明,经过生理生化特征分析、16S rDNA基因序列分析以及系统发育树分析鉴定菌株N3为地衣芽孢杆菌（Bacillus licheniformis）、菌株N5为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）、菌株N7为索诺拉沙漠芽孢杆菌（Bacillus sonorensis）、菌株N11为酸居芽孢杆菌（Bacillus acidicola）。菌株N3、N5、N7和N11的最适生长温度均为45 ℃;菌株N3、N11的最适生长pH值为5.5;菌株N5、N7的最适生长pH值为4.5;菌株N3、N7、N11最适生长盐度（NaCl含量）为1%,菌株N5最适生长盐度（NaCl含量）为2%;4株菌在LB液体培养基中均具有较快的生长速度和较强的繁殖能力。     

Comparative study of the chemical composition and nutritional value of pumpkin seed cake, soybean meal and casein

The chemical composition and nutritional value of pumpkin (Cucurbita pepo) seed cake (PSC) were studied and compared with those of casein and soybean meal. Crude protein and ether extract content in dry matter of PSC was 598.0 g/kg and 124.6 g/kg, respectively, and was higher than the percentage of these components (474.2 and 28.3 g/kg, respectively) in soybean meal used in this experiment. The main fatty acids in PSC cake were oleic acid (50.4%) and linoleic acid (29.9%). Protein found in PSC contained considerable quantities of tryptophan (1.54 g/16 g N); by contrast, the content of lysine (3.21 g/16 g N) and isoleucine (3.83 g/16 g N) was low. Small quantities of phenolic compounds (2.61 g/kg), low activity of trypsin inhibitors (1.33 TUI/mg) and small quantities of alpha-galactosides (19.9 g/kg) were found in PSC. Among antinutritive components only the content of inositol phosphates in PSC (40.5 mg/g) was higher than in soybean meal (10.8 mg/g). True digestibility coefficient (TD) of PSC protein was similar (83.1%), but protein efficiency ratio (PER) was lower (1.01) in comparison with soybean meal (83.5% and 1.50, respectively). After supplementation with lysine, TD (85.9%) and PER (1.43) in PSC were comparable with TD and PER to soybean meal. The PSC-soybean meal mix diet (protein ratio 1:1) had a higher PER value than the diet with soybean meal only (1.98 vs. 1.50).     

Effects of ultrafiltration of whole milk on some properties of spray-dried milk powders

The objective was to produce spray-dried milk powders for assessment subsequently in chocolate. Milks were ultrafiltered to increase their protein content (3.08–5.33 g 100 g⁻¹), concentrated to different solids levels (42.8–52.3 g 100 g⁻¹) and spray-dried to produce powders (26–59 g 100 g⁻¹ fat). The relationships between the milk protein content, concentrate viscosity and some powder properties were quantified. The free-fat content of the powders increased linearly to 74 g 100 g⁻¹ fat with milk protein content for 26 and 40 g 100 g⁻¹ fat powders. The particle size and moisture content of the powders increased linearly with concentrate viscosity for 26 g 100 g⁻¹ fat powders. Differences between the control and ultrafiltration-treated milk powders were explained. The free-fat content and the particle size increased with the fat content of the control powders. The vacuole volume of the powders was inversely more related to the free-fat content than to the fat content of the control powders.     

Optimisation study of gum extraction from Basil seeds (Ocimum basilicum L.)

Basil seed ( Ocimum basilicum L.) is cultivated in large quantities in different regions of Iran. This seed has reasonable amounts of gum with good functional properties which is comparable with commercial food hydrocolloids. A central composite rotatable design was applied to evaluate the effects of temperature, pH and water/seed ratio on the yield, apparent viscosity and protein content of water-extracted Basil seed gum. All of the variables significantly ( P  < 0.05) affected the extraction yield, whereas the effect of water/seed ratio on apparent viscosity and the effects of pH and water/seed ratio on protein content were not significant ( P  > 0.05). Numerical optimisation determined the optimum extraction conditions based on the highest yield and viscosity and the lowest protein content as being temperature 68.71 °C, pH 8.09 and water/seed ratio 65.98:1. Power law model well described non-Newtonian pseudoplastic behaviour of BSG. Flow behaviour index ( n ) and consistency index ( K ) of 1% crude and pure BSG samples were 0.306, 0.283 and 17.46, 20.22 Pa s ⁿ , respectively.     

Isolation of Tomato Seed Meal Proteins with Salt Solutions

Salt solutions were used in isolating tomato seed meal proteins. Na₂SO₃ and NaCl solutions at different concentrations, and pH were included in a central composite design to find optimum conditions of protein isolation. The highest total protein yield was achieved with water extraction (no salt present). Salt extraction at pH 7.5 produced isolates with protein content of 93.4% (NaCl 5% w/v) and 77.1% (Na₂SO₃ 0.5% w/v). Observed values were in good agreement with predicted values. Isolates extracted with different salt solutions ranged from less soluble but very resistant to heat and Ca²⁺, to very surface active with functional properties comparable to commercial soy isolates.     

Effect of polyphenol and pH on cocoa Maillard-related flavour precursors in a lipidic model system

Polyphenol and pH influence the flavour quality of cocoa beans during roasting. Amino acids and reducing sugars are flavour precursors in cocoa beans, which develop into cocoa-specific aroma through Maillard reactions during roasting. A central composite design was applied to determine the combined effect of polyphenol and pH on the flavour precursors during cocoa roasting at 120 °C for 45 min using a lipidic model system. Polyphenol was added at 40, 80 and 120 g kg⁻¹ and pH was adjusted to 4.5, 6 and 7.5. The response surface methodology revealed that a lower concentration of amino acids and reducing sugars was obtained at higher polyphenol concentration (120 g kg⁻¹) and lower pH value (4.5). Based on the constraints set, the best polyphenol concentration of 43–58 g kg⁻¹ and pH of 7.0–7.5 was found to be optimum for the formation of flavour precursors in this lipidic model study.     

Canning of vegetable soybean: procedures and quality evaluations

Some aspects of the preservation process of vegetable soybean are discussed in this paper. Factors, like the effects of blanching duration, and brine composition, were discussed in relation with the quality attributes of the product including enzyme activity, texture and colour. It was observed that the concentration of CaCl₂ influenced the texture and luminosity (L), while the pH affected luminosity (L) and green colour (– a / b ) of the processed product. Furthermore, blanching for 90 s before heat-processing was effective to inactivate 99% of the initial lipoxygenase activity. It was found that a brine containing 150 g L⁻¹ NaCl and 2.9 g L⁻¹ CaCl₂, at pH 6.5 that was thermally treated for 9 min generated a lethality of 4 min that is enough to produce a 12-log reduction required for low acid foods and at the same time retaining desirable colour and texture.     

Effect of pretreatment conditions on physicochemical parameters of carrot juice

Carrot juice obtained by hydraulic press with wooden set-up was subjected to pretreatments (temperature, time and pH) prior to extraction process. Their effects on the most important quality parameters of carrot juice, such as beta-carotene, reducing sugars, pectin, vitamin C, viscosity, pH and acidity were studied. Response surface methodology was employed, where the experiment was carried out according to a central composite rotatable design. The variables ranges used were 61.50–98.50 °C (temperature), 124.55–595.45 s (time) and 2.31–6.69 (pH – concentration of citric acid). The results showed that beta-carotene extraction was significantly increased (52.9%) with these pretreatments in comparison to control samples. All the derived mathematical models for the responses were found to be fit significantly to predict the data. The responses were optimised by numerical method and were found to be 7190 μg per 100 g beta-carotene, 3.41% reducing sugars, 4.96 mg per 100 g vitamin C, 0.59% pectin, 1.64 × 10³ Ns m⁻² viscosity, 5.26 pH and 4.97% acidity at optimum input variables of 75.26 °C (temperature), 349.89 s (time) and 3.2 (pH). The desirability for all the responses was found to be 83.8%.     

Nutritional Characteristics of Distiller's Spent Grain

Five distiller's spent grain (DSG) samples were analyzed for their compositional and nutritional (protein efficiency ratio, PER) values. The protein content (N × 6.25) of these samples ranged from 26.9–34.9% (air-dry basis). True protein content, however, was substantially lower. Dietary fiber content of samples ranged from 29.1–35.8%. Samples contained about 3% nucleic acid. All samples contained appreciable amounts of potassium, magnesium, phosphorus, zinc, copper, iron, chromium, thiamin, riboflavin and niacin. The lysine content of DSG samples ranged from 2.50–3.74 g/100g protein. Except for one sample (PER, 1.7), the quality of protein in the samples was low (PER, 0.6 ± 0.1).     

Importance and utilization of amaranth in food industry. Part 2. Composition of amino acids and fatty acids

Content of amino acids and fatty acids in whole amaranth flour from Amaranthus hypochondriacus was investigated. In comparison with fine wheat flour, used in our experiments, high lysine content was observed (5,95 g/16 g N in comparison with 2,90 g/16 g N). Similarly, a higher amount of essential amino acids in amaranth was found. The highest content from fatty acids had linoleic acid about 50%. On the basis of the results obtained, the analysed raw material proves to be very valuable for the enrichment of some cereal products especially regarding protein content, amino acid composition, mainly essential ones, fatty acid composition, and some important mineral substances and vitamins. It is expected, that amaranth will be utilized in some branch of food industry as well.     

Selenium content in selected products of animal origin and estimation of the degree of cover daily Se requirement in Poland

The aim of the study was to determine Se concentration in selected products of animal origin (dairy products, pork, beef, chicken, giblets, fish, eggs) and to estimate the degree to which these products cover daily Se requirement in humans. Selenium concentrations were determined using the spectrofluorometric method. Mean Se concentration in the milk, yoghurt, kefir, and probiotic drinks was 0.020 μg mL⁻¹, 0.010 μg mL⁻¹, 0.012 μg mL⁻¹ and 0.012 μg mL⁻¹, respectively. Selenium concentration in cheese ranged 0.022–0.088 μg g⁻¹ wet weight. The average selenium content of meat ranged from 0.064 (beef) to 0.094 (chicken) μg g⁻¹ w.w. The mean Se content of giblets (liver: 0.307–0.401 μg g⁻¹ w.w.) was significantly ( P  < 0.05) higher than in meat. The concentration of Se depends on fish species and in our study it ranged from 0.136 ± 0.023 (flounder) to 0.282 ± 0.024 μg g⁻¹ w.w. (mackerel). The results obtained show that the analysed food provides 22.8% of the daily selenium requirement. Considering that animal products account for 40–45% of the diet daily selenium intake averages 33–37 μg.     

响应面法优化猪肉盐溶蛋白热诱导凝胶工艺的研究

研究pH值、NaCl、MgCl2和复合磷酸盐(MP)对猪后腿肉盐溶蛋白(SSP)提取率及热诱导凝胶的保水性(WHC)和凝胶强度(BS)的影响。通过数学模型的建立和响应面分析,确定制备热诱导凝胶的最佳工艺条件。结果表明,在pH6.7、NaCl 0.7mol/L、MgCl2 0.006mol/L、MP 2.5g/kg处理条件下,盐溶蛋白提取率为9.41%、凝胶保水性为86.13%、凝胶强度为86.50g。MgCl2与MP的交互作用显著增加盐溶蛋白的溶出率。各因素间的协同作用对热诱导凝胶的品质有显著影响。     

Optimization of the production of acetylated distarch adipates using the novel software 'MULTIPLEX'

Acetylated, cross-linked and pregelatinized cassava starches were produced in a single-screw extruder with different moisture contents (180, 220 and 260 g kg^–1), reagent (adipic acetic mixed anhydride) concentrations (4, 11 and 18 g kg^–1) and screw speeds (100, 130 and 160 r.p.m.). The acetylation, cross-linking and pregelatinization increased cold viscosity (CV), water absorption index (WAI) and gel hardness, it also reduced gel cohesiveness, paste clarity and retrogradation of the modified-starches compared with control samples (CSs). A novel microcomputer program called MULTIPLEX was developed for the optimization of the process. The optimization process maximized CV, WAI, gel hardness and paste clarity, and minimized gel cohesiveness and retrogradation of the modified-starches. The optimum conditions were moisture of 240 g kg^–1, reagent concentration of 4 g kg^–1 and screw speed of 100 r.p.m. Experimentally determined values for all responses found in products processed under the optimum conditions were very close to the predicted values and this confirmed the validity of predicted models.     

Optimization of processing parameters for the ultrasonic extraction of goat kid rennet

Using abomasums of 2- to 3-week-old goat kids as material, the effects of some factors such as ultrasound intensity, extraction time, NaCl concentration in extraction solution and ratio of abomasums mucosa to extraction solution on the extraction yield of goat kid rennet were investigated. On the basis of single factor experiments, the processing parameters for ultrasound extraction were optimized using a four-factor orthogonal and rotatory combinatorial design. The results showed that the optimum processing parameters for the extraction of goat kid rennet were: ultrasound intensity, 44 W/cm²; extraction time, 25 min; NaCl concentration in extraction solution, 16%; and the ratio of abomasumal mucosa to extraction solution, 1 : 30. In addition, the ultrasonic extraction, as compared with traditional extraction, proved to be more effective.     

RESPONSE SURFACE METHODOLOGY STUDY ON THE POSSIBILITY OF NITRITE REDUCTION BY GLUCONO-δ-LACTONE AND ASCORBIC ACID IN TURKISH-TYPE FERMENTED SAUSAGE (SUCUK)

The primary goal of this study was to determine the residual nitrite-reducing effects of glucono-δ-lactone (GDL) and ascorbic acid (AA) in Turkish-type fermented sausage. Response surface methodology was used to investigate the simultaneous effects of processing variables, e.g., nitrite (0–200 mg/kg sausage), GDL (0–0.5% w/w) and AA (0–500 mg/kg sausage) on pH, moisture, residual nitrite, proteolysis, lipolysis, peroxide, yield and sensory score of the sausage. AA significantly ( P <  0.01) decreased the residual nitrite level; however, quadratic effect of AA showed an inverse effect. GDL did not produce the same effect on the residual nitrite level. The processing variables had no prominent effect on the proteolysis, lipolysis and peroxide. GDL and AA addition showed a negative effect on the yield and sensory scores of the sausages. The regression model predicted the optimum residual nitrite content to be 0.75 mg/kg. The critical values for nitrite, GDL and AA to obtain this optimum level were 147.56 mg/kg, 0.17% and 565 mg/kg, respectively.

PRACTICAL APPLICATIONS

Residual nitrite level is a major problem in the Turkish-type fermented sausage product with respect to some health concerns, residual nitrite causes a possible formation of the carcinogenic N -nitrosamines. The results of this study can be applied to reduce the residual nitrite level in sausage and to find the optimum levels of nitrite, glucono-δ-lactone and ascorbic acid levels to maintain the characteristic sausage quality properties. Based on the results, ascorbic acid can be used to reduce the residual nitrite levels in the sausage.     

Effects of NaCl Concentration on Salting-in and Dilution During Salting-out on Soy Protein Fractionation

ABSTRACT:  Glycinin and β-conglycinin are the main storage proteins in soybeans that can be fractionated by using alkali extraction, SO₂, salting-in with NaCl, salting-out by dilution and pH adjustment to produce a glycinin-rich fraction, a β-conglycinin–rich fraction, and an intermediate fraction, which is a mixture of the two proteins. Two different strategies were employed to optimize the procedure to achieve high efficiency in recovering the β-conglycinin–rich fraction. The first strategy was to optimize salting-in effects of NaCl, and the effects of NaCl concentration on the yields and purities of the protein fractions were investigated. The maximum protein yield of the β-conglycinin–rich fraction was obtained at 500 mM NaCl, but at the expense of purity. The optimum NaCl concentration was 250 mM, at which good protein yield (18.5%) and purity (84.5%) were achieved. At higher NaCl concentrations, the protein yields of the intermediate fractions were significantly lower, and the protein loss in the whey fraction increased. The second strategy was to improve the salting-out step for the β-conglycinin–rich fraction. At 0- and 0.5-fold dilution, the purities and yields of the β-conglycinin–rich fractions were significantly lower than at 1.0- and 2.0-fold dilution. There were no differences in protein yields or purities when using 1.0- or 2.0-fold dilution. According to these results, the recommended NaCl concentration for the salting-in step is 250 mM and the dilution factor for salting-out is 1.0.