Efficient sorption of polyphenols to soybean flour enables natural fortification of foods

The present study demonstrated that defatted soybean flour (DSF) can sorb polyphenols from blueberry and cranberry juices while separating them from sugars. Depending on DSF concentration and juice dilution, the concentration of blueberry anthocyanins and total polyphenols sorbed to DSF ranged from 2-22 mg/g and 10-95 mg/g, respectively while the concentration of anthocyanins and proanthocyanidins in cranberry polyphenol-enriched DSF ranged from 2.5-17 mg/g and 21-101 mg/g, respectively. Blueberry polyphenols present in one serving of fresh blueberries (73 g) were delivered in just 1.4 g of blueberry polyphenol-enriched DSF. Similarly, one gram of cranberry polyphenol-enriched DSF delivered the amount of proanthocyanidins available in three 240 ml servings of cranberry juice cocktail. The concentration of blueberry anthocyanins and total polyphenols eluted from DSF remained constant after 22 weeks of incubation at 37 °C, demonstrating the high stability of the polyphenol-DSF matrix. LC-MS analysis of eluates confirmed that DSF retained major cranberry and blueberry polyphenols intact. Blueberry polyphenol-enriched DSF exhibited significant hypoglycaemic activities in C57bl/6J mice, and cranberry polyphenol-enriched DSF showed antimicrobial and anti-UTI activities in vitro, confirming its efficacy. The described sorption process provides a means to create protein-rich food ingredients containing concentrated plant bioactives without excess sugars, fats and water that can be incorporated in a variety of scientifically validated functional foods and dietary supplements.     

Frozen Wild Blueberry-Tofu-Soymilk Desserts

Both wild (lowbush) blueberries (Vaccinium angustifolium Ait.) and soybeans (Glycine max L.) possess a variety of antioxidants, and both foods appear to have multiple health benefits. Our objectives were to identify whether wild blueberry juice concentrate was more acceptable than puree in frozen desserts with a soy milk‐tofu base; to determine whether fat‐free products were as acceptable as those with 10% added fat; and to compare several levels of blueberry juice concentrate. Four frozen dessert formulations were prepared in duplicate from soy milk, silken tofu, sucrose, stabilizer, BJC or puree, soybean oil or polydextrose, sweetened dried blueberries, salt, and lemon juice. Samples were assayed for total anthocyanins, antioxidant activity using the DPPH method, color, overrun, and solids. Fifty‐five persons evaluated the samples using a 9‐point hedonic scale for color, flavor, texture, and overall acceptability. Samples containing blueberry juice concentrate were darker and less blue. Anthocyanin levels were highest in the puree sample and the fat‐free product with 7.8% blueberry juice concentrate. However, antioxidant activity was highest (28 Trolox equivalents per gram) in the samples made with soybean oil and 7.4% blueberry juice concentrate. The puree formulation received higher hedonic scores than did the low‐fat blueberry juice concentrate formulations. The puree formulation received overall acceptability scores of like very much or like extremely by 45% of the consumers. These findings may aid processors in defining potential formulations that combine 2 healthful food ingredients.     

FORMULATION OF BEVERAGES CONTAINING BYPRODUCTS OF OSMOTIC DEHYDRATION OF LOWBUSH BLUEBERRIES

The manufacture of osmotically dehydrated lowbush blueberries, Vaccinium angustifolium, produces a liquid byproduct, blueberry extract (BE), containing sugar and blueberry juice. The unique blueberry color and flavor in BE were utilized in a simple beverage containing spring water, 30% or 50% BE (w/v), and 0.1% or 0.2% citric acid. The beverages with 50% BE had significantly higher (p ≤ 0.001) brix and were significantly (p ≤ 0.001) darker, less red, and more blue. Fifty consumers rated the beverages containing 50% BE as significantly more acceptable in color (p ≤ 0.001) and fruit flavor (p ≤ 0.05), but least acceptable (p ≤ 0.001) for sweetness. Samples with 0.2% citric acid were significantly higher (p ≤ 0.001) in overall acceptability. BE can be used to provide flavor and color in fruit beverages while reducing a waste disposal problem for blueberry processors.     

Frozen Blueberry-soy Dessert Quality

ABSTRACT: Lowbush or wild blueberries ( Vaccinium angustifolium Ait.) and soy protein offer many complementary health benefits; thus, combinations of these 2 foods may appeal to health-conscious consumers. Four frozen dessert formulations were prepared with soy protein isolate and different amounts of blueberry concentrate and puree. Fat content (3% or 10%) was adjusted with soybean oil and nondairy creamer. Consumers ( n = 40) from the campus community used a 9-point hedonic scale to assess acceptability. The 10% fat content and 8.6% blueberry concentrate formulation received the highest overall acceptability (6.63, P < 0.05), compared with formulations with 10% fat and 17.2% blueberry concentrate and 3% fat and 12.9% blueberry concentrate. More than 1 /3 of the panelists are trying to increase blueberry consumption, 20% want to increase soy, and 20% want to eat more of both foods. Development of palatable desserts combining lowbush blueberries and soy protein could lead to increased consumption of both healthy ingredients.     

Storage effects on anthocyanins, phenolics and antioxidant activity of thermally processed conventional and organic blueberries

BACKGROUND: Consumer demand for products rich in phytochemicals is increasing as a result of greater awareness of their potential health benefits. However, processed products are stored for long‐term and the phytochemicals are susceptible to degradation during storage. The objective of this study was to assess the storage effects on phytochemicals in thermally processed blueberries. Thermally processed canned berries and juice/puree were analysed for phytochemicals during their long‐term storage. RESULTS: The phytochemical retention of thermally processed blueberries during storage was not influenced by production system (conventional versus organic). During 13 months of storage, total anthocyanins, total phenolics and total antioxidant activity in canned blueberry solids decreased by up to 86, 69 and 52% respectively. In canned blueberry syrup, total anthocyanins and total antioxidant activity decreased by up to 68 and 15% respectively, while total phenolic content increased by up to 117%. Similar trends in phytochemical content were observed in juice/puree stored for 4 months. The extent of changes in phytochemicals of thermally processed blueberries during storage was significantly influenced by blanching. CONCLUSION: Long‐term storage of thermally processed blueberries had varying degrees of influence on degradation of total anthocyanins, total phenolics and total antioxidant activity. Blanching before thermal processing helped to preserve the phytochemicals during storage of blueberries. Copyright © 2011 Society of Chemical Industry     

Identification and analysis of isothiocyanates and new acylated anthocyanins in the juice of Raphanus sativus cv. Sango sprouts

The freeze-dried sprouts’ juice of Raphanus sativus (L.) cv. Sango was prepared and analysed for the first time. HPLC analysis of total isothiocyanates, after protein displacement, resulted in 77.8 ± 3.0 μmol/g of dry juice while GC–MS analysis of hexane and acetone extracts showed E- and Z-raphasatin (8.9 and 0.11 μmol/g, respectively) and sulforaphene (11.7 μmol/g), summing up to 20.7 ± 1.7 μmol/g of free isothiocyanates. Sprouts’ juice contained an unprecedented wealth of anthocyanins and a new fractionation methodology allowed us to isolate 34 mg/g of acylated anthocyanins (28.3 ± 1.9 μmol/g), belonging selectively to the cyanidin family. Analysis was performed by HPLC–PDA–ESI–MSⁿ and extended to deacylated anthocyanins and aglycones, obtained, respectively, by alkaline and acid hydrolysis. This study identified 70 anthocyanins, 19 of which have never been described before and 32 of which are reported here in R. sativus for the first time. Sango radish sprouts are exceptional dietary sources of heath-promoting micronutrients.     

Antioxidant activity,anthocyanins, and phenolics of rabbiteye blueberry (Vaccinium ashei) fluid products as affected by fermentation

Frozen rabbiteye blueberries (Vaccinium ashei) were processed into juice (BJ), wines made without (BW1) or with (BW2) skin contact fermentation, and vinegars made from BW1 (JV), BW2 (WV) or blueberries (BV). Total phenolics, total anthocyanins, antioxidant activities (beta-carotene bleaching assay and ferric thiocyanate assay), and antiradical activity (DPPH radical-scavenging method) of these fluid products were determined. The differences in total anthocyanin contents of all blueberry products were significant. The BW2 had the highest content of anthocyanins and polyphenols and the highest beta-carotene bleaching activity and antiradical activity. Acetification decreased total anthocyanin content, total polyphenols and antioxidant activities. Correlations indicate that anthocyanins made significant contributions than did phenolics to antioxidant activities of products. The abilities of BJ, BW1 (wine from blueberry juice), and BW2 to inhibit linoleic acid peroxidation were high (∼95%). The abilities of vinegar products to inhibit linoleic acid peroxidation were low. The results indicate that skin-contact fermentation is a better method for obtaining higher antioxidant activity of blueberry products. Also, acetification significantly decreased anthocyanins and antioxidant activities.     

Purification,characterisation, and quantification of the soy allergen profilin (Gly m 3) in soy products

Profilins are pan-allergen proteins present in various plant foods and pollens. The objective was to develop a method for purification and characterisation of profilin from soy protein isolate. Furthermore, profilin was quantified in soy products and the effect of processing evaluated. Profilin was purified using poly-l-proline affinity chromatography, dialysis and ultrafiltration, and its quantification was implemented by indirect ELISA. Profilin in soymilks ranged from 4.37 ± 0.14 to 7.24 ± 0.30 mg/g protein, while in fermented products profilin ranged from 1.67 ± 0.02 to 5.47 ± 0.02 mg/g protein. Pasteurisation of soymilk was an ineffective method to completely eliminate profilin. Food matrix influenced thermal stability; at 100 °C, β-sheet and random coil structures were altered, while the α-helices remained intact. Induced fermentation of soybean meal by Bifidobacterium lactic, Lactobacillus plantarum and Saccharomyces cerevisiae resulted in 68.3% to 72.7% reduction of soy profilin. Heat treatment, fermentation and hydrolysis effectively reduced soy profilin.     

Optimization of a chocolate-flavored, peanut-soy beverage using response surface methodology (RSM) as applied to consumer acceptability data

Optimization of a chocolate-flavored, peanut-soy beverage was done using response surface methodology (RSM). Twenty-eight beverage formulations were processed by mixing three basic ingredients: peanut (X₁=30.6 g/100 g-58.7 g/100 g), soy (X₂=28.3 g/100 g-43.5 g/100 g), and chocolate syrup (X₃=13.0 g/100 g-25.9 g/100 g). The proportions of these ingredients were obtained using a three component, constrained mixture design where the source of soy was either flour (SF) or protein isolate (SPI). Consumer acceptability was measured in terms of nine response variables by 41 consumers using a 9-point hedonic scale. Parameter estimates were determined by performing regression analysis with no intercept option. l-pseudo-components were introduced to get equivalent second degree models further used to generate contour plots. The regions of maximum consumer acceptability [hedonic rating ?5.0 since the control (commercial chocolate milk) ratings were 6.0-7.0] were identified and marked on these contour plots for each sensory response. Superimposition of contour plots corresponding to each response variable resulted in optimum regions having consumer acceptability ratings ?5.0. Optimum formulations were all the combinations of X₁: 34.1 g/100 g-45.5 g/100 g, X₂: 31.2 g/100 g-42.9 g/100 g, and X₃: 22.4 g/100 g-24.1 g/100 g for SF-based; and X₁: 35.8 g/100 g-47.6 g/100 g, X₂: 31.2 g/100 g-43.5 g/100 g, and X₃: 18.3 g/100 g-23.6 g/100 g for SPI-based beverage formulations.     

Fructooligosaccharide fortification of selected fruit juice beverages: Effect on the quality characteristics

Fortification of selected fruit juice beverages (Pineapple, Mango and Orange juice) with fructooligosaccharides (FOSs), a low calorie prebiotic has been discussed. Results indicated that sucrose which is usually used as a sweetener in fruit juice beverages can be partially substituted with FOS without significantly affecting the overall quality. The fruit juice beverages were evaluated for physicochemical and sensory changes during 6 months storage period at ambient (25 ± 2 °C) and refrigeration temperature (4 °C). The pH, total soluble solids, titratable acidity, and colour did not change significantly (P ≥ 0.05) during storage. The initial FOS content of pineapple, mango and orange juice beverages was 3.79, 3.45, and 3.62 g/100 mL. The FOS content of the fruit juice beverages stored at refrigeration temperature was 2.00-2.39 g/100 mL after 6 months of storage and 2.69-3.32, 1.65-2.08 and 0.38-0.58 g/100 mL at the second, fourth and sixth months of storage at ambient temperature respectively. The sensory analysis showed that the beverages were acceptable up to 4 and 6 months storage at ambient and refrigeration temperature respectively.     

蓝莓酒渣、果、酒中花色苷成分鉴定及酒渣与果中花色苷抗氧化活性比较

采用XAD-7HP大孔树脂对蓝莓果及蓝莓酒渣花色苷进行纯化,用固相微萃取小柱对蓝莓酒花色苷进行纯化浓缩。通过高效液相色谱-二极管阵列-电喷雾-串联质谱法鉴定了蓝莓果、酒渣、酒中花色苷的组成,并对蓝莓果和蓝莓酒渣花色苷的抗氧化性进行了评价。结果表明：通过XAD-7HP大孔树脂纯化所得的蓝莓果、蓝莓酒渣及利用固相微萃取小柱纯化所得的蓝莓酒中花色苷含量分别为（210.52±5.74）、（151.12±0.88）、（8.93±0.14）mg/g。蓝莓果中鉴定出11 种花色苷;蓝莓酒渣中鉴定出12 种花色苷,其中包括3 种酰化花色苷;蓝莓酒中鉴定出9 种花色苷,其中包含1 种酰化花色苷。蓝莓果和蓝莓酒渣花色苷抗氧化性实验结果表明,蓝莓果和蓝莓酒渣花色苷清除2,2-联氮-二（3-乙基-苯并噻唑-6-磺酸）二铵盐自由基IC50值分别为（1.43±0.02）、（1.19±0.03）μg/mL,清除1,1-二苯基-2-苦基肼自由基IC50值分别为（3.28±0.03）、（2.41±0.01）μg/mL;蓝莓果和蓝莓酒渣花色苷清除自由基能力及还原力均显著优于VC,蓝莓酒渣花色苷抗氧化性显著强于蓝莓果花色苷。     

Influence of osmotic concentration,continuous high frequency ultrasound and dehydration on antioxidants,colour and chemical properties of rabbiteye blueberries

Rabbiteye blueberries (Vaccinium ashei Reade) were osmoconcentrated in a sucrose solution for 12 h, and for 3 h, with and without high frequency ultrasound (CHFU). Treated and untreated samples were air-dehydrated (70 °C, 10 h). Osmoconcentration decreased titratable acidity and induced a high loss of anthocyanins and phenolics. Approximately 60% of anthocyanins and phenolics were lost during osmoconcentration for 12 h. Air-dehydration further decreased anthocyanins and phenolics, with a higher negative influence on anthocyanins. Dehydration, after osmotic concentration, produced the largest colour differences in comparison to the control. High frequency ultrasound had a negative influence on anthocyanins and phenolics. Antioxidant activity was lowest in osmoconcentrated and dehydrated berries. Combination of high temperature, high sugar concentration and oxygen availability had the largest negative influence on colour and antioxidant properties (anthocyanins and phenolics) of dehydrated rabbiteye blueberries.     

蓝莓不同部位常规营养成分及活性物质的比较分析

为了研究蓝莓不同部位常规营养成分及活性物质分布情况,以贵州产蓝莓(园蓝)为实验样品,采用比色法、滴定法等,对蓝莓不同部位(果肉、果皮和全果)中的总酸、总糖、黄酮、多酚、花色苷、蛋白质、脂肪、维生素C和灰分含量进行分析测定。结果表明蓝莓果皮中总酸、蛋白质、花色苷、多酚和黄酮的含量分别为(1.927±0.004)mg/g、(0.88±0.04)g/100 g、(1312.4±175.9)mg/100 g、(3.89±0.52)mg/g和(2.85±0.40)mg/g,显著高于果肉和全果(p<0.05);总糖则主要分布在果肉中(p<0.05),但蓝莓果肉中总酸、多酚、黄酮、花色苷的含量却最少(p<0.05)。在蓝莓果汁与果酒的加工中,果皮均被作为加工废料被丢弃,造成了资源的巨大浪费,由于蓝莓果皮的营养成分含量较高,因此有较好的开发前景和深加工利用价值。      

Aglycone production by Lactobacillus rhamnosus CRL981 during soymilk fermentation

Lactobacillus rhamnosus CRL981 showed the highest levels of β-glucosidase and was selected to characterize this enzyme system, among 63 strains of different Lactobacillus species. The maximum activity was obtained at pH 6.4 and 42 °C. The enzyme showed weak resistance to thermal inactivation maintaining only 20% of the initial activity when it was exposed at 50 °C for 5 min. It also, showed stability when stored at 4 °C for 60 days. Afterwards, L. rhamnosus was evaluated for hydrolysis of isoflavones to aglycones, cell population, residual sugars and organic acid produced during fermentation on soymilk (37 °C for 24 h). Higher viable counts were obtained after 12 h of fermentation (8.85 log CFU ml⁻¹) followed by a drop of pH and an increase of acidity during fermentation due the production of organic acids. L. rhamnosus CRL981 was able to proliferate in soymilk and produce a high β-glucosidase activity achieving a complete hydrolysis of glucoside isoflavones after 12 h of fermentation. The present study indicates that L. rhamnosus CRL981 could be used in the development of different aglycone-rich functional soy beverages.     

蓝莓加工过程中出汁率及花青素的稳定性研究

研究果胶酶对蓝莓出汁率的影响,对果胶酶提高蓝莓出汁率的工艺条件进行优化,并研究了pH值、温度、光 照、金属离子以及部分添加剂对蓝莓果汁中花青素稳定性的影响。结果表明：果胶酶的最佳酶解条件为果胶酶添加量（质 量分数）0.06%、酶解温度35 ℃、酶解时间2 h。在此条件下蓝莓的出汁率可达到82.1%,与对照组相比,出汁率提高了 24.6%。蓝莓果汁中的花青素在pH≤3时比较稳定;对光和高温比较敏感。VC可以增加花青素的稳定性,而苯甲酸钠以及 蔗糖对花青素的稳定性无显著影响。K+、Na+、Ca2+、Cu2+、Fe2+对果汁中花青素的稳定性无显著影响;Fe3+以及浓度达到 0.1 mol/L的Mg2+对果汁中花青素的稳定性具有破坏作用;浓度低于0.05 mol/L的Mg2+能增加果汁中花青素的稳定性。     

Blueberry and Grape Anthocyanins as Breakfast Cereal Colorants

ABSTRACT: Fruit anthocyanins provide color and health benefits, thus cereals containing these pigments could be used as functional foods. White corn meal with 10% sucrose was twin-screw extruded with either corn syrup, lowbush blueberry concentrate, or Concord grape-juice concentrate. Extrusion reduced anthocyanins, but there was no change due to storage at room temperature for 3 mo. Polymeric color was higher in the blueberry cereal. The grape cereal was lighter and less red than the blueberry product. Bulk density was highest in the corn-syrup cereal. Overall acceptability was higher for the syrup and grape cereals. Sweetness and flavor acceptability were correlated with overall liking.     

Sensory Characteristics, Shear Values and Cooking Properties of Ground Beef Patties Extended with Iron- and Zinc-Fortified Soy Isolate, Concentrate or Flour

Ground beef patties made from 100% beef or beef extended with 20% rehydrated soy isolate, concentrate, or flour, with or without iron and zinc fortification, were evaluated for sensory, shear and cooking properties. With the exception of patties formulated with soy isolate, soy-added patties were rated as more tender (P <0.05) than all-beef patties. Soy isolate imparted textural characteristics to patties that were more similar to those of all-beef patties than to those of soy concentrate or soy flour extended patties. Patties made with soy flour had the highest cooking yields. Also, patties extended with soy flour had lower incidences of rancid flavor, but higher incidences of soy flavor compared with all other beef-soy formulations. Iron and zinc fortification produced a higher frequency of rancid flavor when used with soy isolate and concentrate.     

High performance liquid chromatography analysis of anthocyanins in bilberries (Vaccinium myrtillus L.), blueberries (Vaccinium corymbosum L.), and corresponding juices

In the present study the anthocyanin content of commercially available bilberry juices and fresh fruits were quantified by using 15 authentic anthocyanin standards via high performance liquid chromatography with an ultra-violet detector (HPLC-UV/VIS). Delphinidin-3-O-glucopyranoside, delphinidin-3-O-galactopyranoside, and cyanidin-3-O-arabinopyranoside were the major anthocyanins found in juices, nectar, and fresh bilberries. In contrast, fresh blueberries had higher concentrations of malvidin-3-O-arabinopyranoside and petunidin-3-O-galactopyranoside. Up to 438 mg anthocyanins per 100 g fresh weight (2762 mg/100 g dry weight (DW)) were detected in blueberries from various sources, whereas bilberries contained a maximum of 1017 mg anthocyanins per 100 g fresh weight (7465 mg/100 g DW). Commercially available bilberry and blueberry juices (n= 9) as well as nectars (n= 4) were also analyzed. Anthocyanin concentrations of juices (1610 mg/L to 5963 mg/L) and nectar from bilberries (656 mg/L to 1529 mg/L) were higher than those of blueberry juices (417 mg/L) and nectar (258 mg/L to 386 mg/L). We conclude that using several authentic anthocyanin references to quantify anthocyanin contents indicated them to be up to 53% and 64% higher in fresh bilberries and blueberries, respectively, than previously reported using cyanidin-3-O-glucoside. This study has also demonstrated that commercially available juices produced from bilberries contain much higher anthocyanin concentrations than those from blueberries. PRACTICAL APPLICATION: We have investigated the contents of a special class of antioxidants, namely anthocyanins in blueberry and billberry fruits and juices commercially available in Germany. To achieve reliable data we have used authentic standards for the first time. We think that our results are important in the field of nutritional intake of this important class of polyphenols and fruit juice companies get a closer insight in the occurrence of these antioxidants in market samples to be used in food composition databases and for nutritional survey.