From Apple to Juice—The Fate of Polyphenolic Compounds

Apples are a rich source of polyphenolic compounds and significantly contribute to the antioxidants in our diet. Apple variety affects the levels of those compounds; concentration can also be reduced during processing, especially juice production. These compounds have been linked with numerous health benefits. Reviews on the apple polyphenolic compounds and their health benefits exist; however, a review on maximizing the retention of the polyphenolic compounds in apple juice has not been compiled. Therefore, the purpose of this paper is to review the literature regarding apple polyphenolic compounds and the effects of processing techniques on their concentration in apple juice.     

Antioxidant Capacity of Fruit Extracts of Blackberry (Rubus sp.) Produced in Different Climatic Regions

A range of blackberry genotypes harvested in different seasons and regions in Mexico (Michoacan) and in the United States (Pacific Northwest) were collected to determine their antioxidant capacity using oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays. Total acidity, ascorbic acid, soluble solids, total phenols, and total anthocyanins, as well as the correlation between all these parameters, were determined for all treatments. Total acidity ranged from 4.22% in wild blackberry from Patzcuaro, Mexico, to 1.02% in ‘Evergreen’ from Woodburn, Oreg. These treatments were also the outliers in terms of ascorbic acid content. Cultivar ‘Brazos’ did not exhibit any significant differences in acidity or ascorbic acid as a consequence of the geographic origin or harvest season. The highest concentration of soluble solids was recorded for ‘Evergreen’ from Woodburn and relatively low soluble solids levels were recorded for all the Mexican treatments. Wild blackberry from Patzcuaro exhibited the highest values for ORAC, FRAP, total phenolic and anthocyanin content. Other relatively high antioxidant capacity values were detected for ‘Marion’ and ‘Evergreen’, both produced in Oregon. Different cultivars grown in the same region/season consistently showed differences in antioxidant capacity. There was little effect of harvest season on phenolic levels. We conclude that levels of total acidity, ascorbic acid, soluble solids, antioxidant capacity, and polyphenols mainly depended on the genotype and not on the climate or the season. ORAC and FRAP values were both highly correlated with each other, and with total phenols and anthocyanin content.     

Ingredient Levels Optimization and Nutritional Evaluation of a Low-calorie Blackberry (Rubus irasuensis Liebm.) Jelly

ABSTRACT:  Response surface methodology (Box-Behnken design) was applied to assess and model effects of 3 factors, sweetener, low methoxyl pectin, and calcium content (each at 3 levels), on the overall acceptability of a blackberry ( Rubus irasuensis Liebm.) jelly, as determined by 100 consumers. Jelly was produced using clarified juice, obtained from a cross-flow microfiltration process. Results showed that the model fit was significant, and there was satisfactory correlation between actual and fitted values (   R  ²= 0.925  and adjusted   R  ²= 0.791  ). The model presented no significant lack of fit ( P = 0.096). Sweetener level had a significant effect on overall acceptability ( P ≤ 0.05), but low methoxyl pectin and calcium levels did not. The statistical model was further used to optimize the factor levels for highest acceptability, in order to obtain a jelly that provided less than 8 calories per serving, making it possible to label the product as "low calorie." The product is a good alternative for consumers who wish to diminish sucrose intake.     

Influence of Fluid Concentration on the Elevation of Boiling Point of Blackberry Juice

The rise in boiling point of blackberry juice was experimentally measured at soluble solids concentrations in the range of 9.4 to 58.4°Brix and pressures between 4.9?×?10³ and 9.0?×?10⁴ Pa (abs.). Different approaches to representing experimental data, including the Dühring's rule, a model similar to Antoine equation and other empirical models proposed in the literature were tested. In the range of 9.4 to 33.6°Brix, the rise in boiling point was nearly independent of pressure, varying only with juice concentration. Considerable deviations of this behavior began to occur at concentrations higher than 39.1°Brix. Experimental data could be best predicted by adjusting an empirical model, which consists of a single equation that takes into account the dependence of rise in boiling point on pressure and concentration.     

纳滤浓缩西番莲果汁的研究

根据西番莲原汁中的有机物组成及分子量,选择合适的纳滤膜对西番莲澄清果汁的浓缩过程进行研究.通过系统考察影响膜通量的因素,发现适当提高温度、压力可以提高膜通量.在不破坏西番莲果汁中的芳香成分及Vc等营养成分和不超过膜的压力操作范围的前提下,得到较适的操作温度和压力.选择在操作温度为28 ℃左右,压力为3 MPa时,分离效果最好,此时实际膜通量达17 L/(m2.h).经过纳滤浓缩,西番莲澄清汁可溶性固形物从13oBx提升到30oBx左右.本实验可以达到较好的膜通量和截留率,为在工业化浓缩西番莲澄清汁过程中,利用膜技术大大减少芳香成分及Vc等营养成分损失提供参考.     

Understanding Nanofiltration Fouling of Phenolic Compounds in Model Juice Solution with Two Membranes

Understanding membrane fouling mechanisms of key nutrition indicators in fruit juices during nanofiltration (NF) are important for quality control of products and manufacture processes. This study evaluated the effects of operating and molecular parameters of six phenolic compounds on fouling resistances during NF with two membranes. Results showed that fouling resistances and mechanisms were significantly different among the six representative phenolic compounds as a result of different molecular parameters such as acidity coefficient, molecular refractive index, octanol-water partition coefficient, and lipo-hydro partition coefficient. Operating time, solution concentration, and transmembrane pressure can also significantly affect the membrane fouling during nanofiltration of gallic acid solution. The images obtained by field emission scanning electron microscopy and atomic force microscopy on new, fouled, and cleaned membranes showed the fouling mechanisms intuitively. For phenolic compounds, a cake/gel layer as a reversible fouling was the main fouling resistance, and the adsorption was a significant role in the irreversible fouling resistance.     

Polyphenolic composition,antioxidant and antiproliferative effects of wild and cultivated blackberries (Rubus fruticosus L.) pomace

The content of total polyphenolics, antioxidative capacity and antiproliferative activity were tested in wild and cultivated blackberry pomace. Wild blackberry pomace extract Tw2 showed the highest following contents: total polyphenolics (50.16 mg GAE g⁻¹ dw), flavonoids (7.73 mg Qc g⁻¹ dw), flavonols (6.63 mg Qc g⁻¹ dw) and total monomeric anthocyanins (13.40 mg Cy g⁻¹). Tw2 extract significantly inhibited free radicals: IC₅₀^DPPH = 127.76 μg mL⁻¹, IC₅₀^ABTS = 26.53 μg mL⁻¹ and IC₅₀ ^{˙ OH} = 168.62 μg mL⁻¹, and the growth of breast adenocarcinoma IC₅₀^MCF7 = 306.68 μg mL⁻¹ and cervix epitheloid carcinoma cell lines IC₅₀^HeLa = 315.49 μg mL⁻¹. Wild blackberry varieties had higher extraction yields, higher total polyphenolic contents and possessed stronger biological effects compared to cultivated blackberries (P < 0.05). All blackberry extracts showed high biological potential that could be attributed to high total polyphenols and flavonoids content and could be utilised as value-added functional food.     

真空浓缩对芒果汁香气成分影响的分析

采用顶空固相微萃取(HS-SPME)技术结合气相色谱-质谱法(GC/MS),对芒果汁在浓缩过程中的香气物质组分进行了分析研究。结果表明在真空浓缩的条件下芒果汁香气成分的种类减少,各组分的含量也降低。而且浓缩芒果汁的糖度越高,香气物质含量减少越多。     

Identification of Ellagic Acid in Blackberry Juice Sediment

ABSTRACT: The sediment in a commercial reconstituted 'Evergreen' blackberry ( Rubus laciniatus L.) juice concentrate was found to be composed of ellagic acid, protein, and other unidentified compounds. The qualitative tannin and protein-tannin haze test indicated that the sediment was predominantly tannin or protein-tannin complexes. Nitrogen determination showed the sediment to be 6.69%± 2.21% protein on a dry-weight basis. Almost all of the extractable material was identified as ellagic acid by high-performance liquid chromatography and liquid chromatography-mass spectrometry. The ellagic acid content of the wet sediment was 0.05 g/100 g, whereas it was 7.41 g/100 g in freeze-dried sediment. Tannase enzyme did not significantly decrease the concentration of ellagitannins in Marion blackberry ( Rubus spp. Hyb.) juice in this study.     

不同加工工艺对黑莓浆果出汁率及果汁品质的影响

三种取汁方法的实验结果表明,制取黑莓果汁采用酶法液化法,出汁率、果汁澄清度、可溶性固形物含量高;直接榨汁法出汁率和可溶性固形物含量较高,但果汁浑浊;浸提取汁法出汁率低,果汁稀薄,可溶性固形物含量低,但色素获得率高.酶解正交试验结果表明,果胶酶用量0.04%～0.06%,处理时间1～2h,处理温度45～55℃,黑莓浆果出汁率高,果汁得率在80%以上,果汁澄清,质量好,果汁透光率在90%左右.     

Folin-Ciocaileu比色法测定蜂花粉中的总酚

蜂花粉含有丰富的多酚类化合物，这类化合物具有抗动脉硬化、降低胆固醇、抗氧化和抗辐射等作用，因此可以用来评价蜂花粉的活性。本文采用Folin-Ciocaileu法对蜂花粉中的总酚进行检测。本方法以原儿茶酸为对照品，标准曲线的回归方程为：C=7．9234A-0．0157（RZ=0．9999）；对稳定性、精密度、重现性、回收率进行了试验，相对标准偏差（RSD）为0．05％-1．43％。该方法简便、快速、准确，是检测蜂花粉中总酚的可靠方法。     

乳酸菌发酵黑莓汁的主要组分和功能活性

以黑莓汁为原料,选用发酵乳杆菌（Limosilactobacillus fermentum）PC11、副干酪乳杆菌（Lactobacillus paracasei）PC18、副干酪乳杆菌（Lactobacillus paracasei）NT4-7、植物乳杆菌（Lactobacillus plantarum）P-S1016 分别进行发酵,研究发酵前后黑莓汁中花色苷含量、总酚含量以及抗氧化活性的变化,并且检测其对皮质酮损伤肾上腺嗜铬细胞瘤细胞株PC12 的保护作用。结果表明：与未发酵黑莓汁相比,乳酸菌发酵黑莓汁的总酚含量以及花色苷含量均有所降低,花色苷保留率较高的是L.plantarum P-S1016 发酵组,为89.65%,总酚含量最高的为L.fermentum PC11 发酵组,保留率88.7%;经4 株乳酸菌发酵后,黑莓汁DPPH 自由基清除率、PTIO 自由基清除率以及FRAP 值显著提高,羟自由基清除率达到90%以上;与未发酵黑莓汁相比,乳酸菌发酵均能显著提高皮质酮损伤的PC12 细胞存活率,其中,L.plantarum P-S1016 和L.paracasei PC18 发酵黑莓汁的细胞存活率相较于损伤组提高了54%和45%。4 种乳酸菌接种发酵显著改善了黑莓汁的品质和抗氧化特性,提高了皮质酮损伤PC12 细胞的存活率,为黑莓汁乳酸菌发酵加工及乳酸菌果汁饮料产品开发提供参考。     

响应面法优化固定化果胶酶制备黑莓汁工艺

利用固定化果胶酶处理黑莓浆,可以提高黑莓的出汁率,降低生产成本,提高企业经济效益。在单因素试验基础上,通过Design-Expert软件进行影响因素响应面分析,优化固定化果胶酶制备黑莓汁的工艺条件。结果显示,影响因素的影响大小顺序为:固定化果胶酶水解温度固定化果胶酶水解时间固定化果胶酶使用质量黑莓p H;响应面分析试验得到黑莓出汁率回归方程,方程达到极显著水平(F=50.48;P0.000 1),拟和很好(R2Pred=0.794 5;R2Adj=0.965 3);固定化果胶酶制备黑莓汁优化工艺参数为:30 g黑莓浆使用固定化果胶酶为5 g、固定化果胶酶水解时间为1.0 h、固定化果胶酶水解温度为52℃;利用优化工艺,平均黑莓出汁率达到70.83%。固定化果胶酶重复使用13次,第13次黑莓出汁率为65.91%(对照组62.37%)。     

超声辅助酶解制备黑莓清汁工艺及其协同效应

针对黑莓果汁加工过程中存在的出汁率低、品质不稳定等问题,运用响应面法研究超声波辅助复合酶（果胶酶＋果浆酶）制备黑莓清汁的优化工艺条件,并对超声波辅助酶解提高黑莓果汁品质的协同效应进行解析。结果显示,超声辅助酶解制备黑莓清汁的最佳工艺条件为超声功率200 W、加酶量0.3%、酶解时间1.5 h、酶解温度45 ℃,在此优化条件下制备的黑莓清汁具有较高的出汁率（80.89%）和透光率（68.21%）,对其品质和色泽稳定性分析得出,其花色苷含量和总酚含量明显高于单一酶解组,且色泽呈红色,在贮藏过程中具有较好的稳定性。采用扫描电子显微镜对处理后原料进行观察,结果表明,超声与酶产生协同效应,加速原料组织结构的破坏,提高黑莓清汁的制备效率。     

Experimental Investigation of the Sweet Whey Concentration by Nanofiltration

The main goal of our work was to examine the possibility of using membrane separation to concentrate sweet whey, which could then be used as the basis of more products (e.g., ice cream, soft drinks containing whey).Whey from cheese making was concentrated by nanofiltration. The operating parameters were determined in permeate recirculation mode, and the concentration experiment was carried out under optimal conditions. The analytical assay of the permeate and concentrate such as total soluble solid content (TSS), protein content, and lactose content was determined using infrared measurements. The retention of lactose was over 95% up to 3.0 volume concentration ratio (VCR) at 20-bar transmembrane pressure. The analysis of the process was based on the resistance in series model and the van’t Hoff law. The model parameters were determined on the basis of lactose content, assuming that lactose is the key component of whey. The values of these parameters are the concentration polarization (β = 1.68) and total resistance (R _TOT = 1.60 × 10¹⁴ m⁻¹). The procedure was also repeated based on TSS, and the value of the total resistance was almost the same (R _TOT = 1.59 × 10¹⁴ m⁻¹). Due to this, the applied models describe appropriately the batch membrane concentration process of whey. The lactose concentration can be used for the calculation instead of TSS, which simplifies the job of estimating the model parameters.