Antioxidant and functional properties of a high dietary fibre powder from carambola (Averrhoa carambola L.) pomace

The use of carambola pomace as a raw material for the production of a high dietary fibre powder (HDFP) was investigated. A face‐centred design was used to study the effects of extraction conditions, namely water‐to‐pomace ratio, time and temperature, on both reducing sugars (RS) and total extractable polyphenols (EPP) contents of fibre concentrate. RS content decreased by increasing extraction times and water‐to‐pomace ratios, while EPP tend to diminish by increasing temperature and contact time (P < 0.01). Selected HDFPs showed an EPP content in the range of 5.0–6.1 g GAE 100 g^?1 dry basis (db), with antioxidant activities between 386.2–443.9 and 204.7–228.6 μmol Trolox equivalents g^?1 db according to FRAP and ABTS assays, respectively. HDFP obtained at 55 °C, 5 min and 2:1 water‐to‐pomace ratio exhibited the highest EPP content, total dietary fibre (84.0% db) and dietary indigestible fraction (61.3% db). This product can be considered as a potential valuable food ingredient considering their oil retention and swelling capacities.     

Effects of pineapple pomace fibre on physicochemical properties of composite flour and dough,and consumer acceptance of fibre‐enriched wheat bread

Pineapple pomace fibre (PF, containing 70.2% total dietary fibre) can be added to increase dietary fibre of wheat bread. This study was performed to evaluate effects of PF added at 0, 5 or 10% (wheat flour‐basis) on physicochemical properties of the composite flour (wheat flour as the control, CPF‐5 and CPF‐10, respectively) and its dough, to evaluate consumer acceptance of CPF breads and to identify factors affecting willingness to purchase of CPF breads. Incorporating PF affected rheological and pasting properties of CPF. Water‐ and oil‐holding capacity of CPF increased (P < 0.05) as PF levels increased. Bread made with CPF‐5 was more acceptable than that with CPF‐10; however, it was not significantly different from the control, having similar specific volume and texture, but having about three times higher total dietary fibre than the control (4.4% vs. 1.5%). Product label and health benefit information potentially affected consumers' willingness to purchase of fibre‐enriched bread.     

纤维素酶对苹果肉渣膳食纤维物化特性的影响

以苹果肉渣为原料,采用X-cell纤维素酶法对苹果肉渣中的水溶性膳食纤维进行提取及工艺优化,对其持水力、膨胀力、表观黏度以及超微结构等物化性质进行分析。得出X-cell纤维素酶优化工艺条件为:酶用量75 U/g,酶解温度50℃,最适pH值为4.6,酶解时间为5 h。在该条件下,可溶性膳食纤维提取率可达18.90%。改性后滤渣水不溶性膳食纤维的持水力和膨胀力有所提高;可溶性膳食纤维溶解性较高,其表观黏度降低。在红外光谱图下,改性前后的膳食纤维都有糖的特征吸收峰,并在电镜下观察可得其超微结构也有所改变。     

Physicochemical properties and bioactive function of Japanese grape (Hovenia dulcis) pomace insoluble dietary fibre modified by ball milling and complex enzyme treatment

The study investigated the effects of ball milling and enzymolysis on the structural characteristics, physicochemical properties and bioactive function of Hovenia dulcis pomace insoluble dietary fibre (HIDF). Ball milling and enzymolysis effectively decreased the particle size and zeta potential of HIDF. The swelling power (SP), water solubility index (WSI) and apparent viscosity of HIDF were effectively enhanced (P < 0.05) after ball milling and enzymolysis. Scanning electron microscopy detection showed that the surface and internal structures of HIDF were destructed by the modified treatment. Ball milling and enzymolysis treatment disrupted the intermolecular hydrogen bonds and crystalline structure of HIDF per Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Furthermore, the inhibition rate of HIDF on α-glucosidase and α-amylase was significantly increased by modification. All HIDF significantly improved the lipid metabolism of hyperlipidemic mice, with the modified IDF providing a stronger effect.     

Evaluation of physicochemical characteristics,nutritional composition and antioxidant capacity of Chinese organic hawthorn berry (Crataegus pinnatifida)

Hawthorn berry (Crataegus pinnatifida), approved as ‘medicine food homology’ fruit by China’s National Health Commission, has been associated with positive effects on human health. In-depth study of nutritional composition and antioxidant capacity can provide basic information on food value of Chinese organic frozen (OFHB)/freeze-dried (OFDHB) hawthorn berries. Higher levels of dietary fibre, pectin, ascorbic acid, mineral and antioxidant capacity were found compared with some common fruits and other species hawthorn. Both OFHB and OFDHB samples have much higher content of potassium (1.02 × 10⁴ and 9.73 × 10³ mg kg⁻¹) than sodium (54.23 and 42.31 mg kg⁻¹). OFDHB had a more desirable ratio (2.68:1) of insoluble/soluble dietary fibre which is suitable for use as a food ingredient. Antioxidant capacity varied considerably depending on the part (peel > pulp) and reaching up to 577.5 µmol Trolox equivalent g⁻¹. OFHB and OFDHB are excellent natural nutrient-dense and antioxidant sources for dietary supplements and functional foods development.     

Use of berry pomace to replace flour,fat or sugar in cakes

Pomace from fruit juice production is a by‐product with a high fibre and bioactive compound content. It is commonly used as animal feed, so using it in food brings added value. The present study assessed the effect of using black currant and aronia pomace to replace either part of the flour, fat or sugar in sponge cakes. Batters in which sugar was replaced showed the highest viscosity. On the other hand, flour replacement led to batters with the lowest viscosity and gave place to softer cakes with fewer but larger‐sized air cells. Sugar replacement conferred greater hardness and a larger number of small air cells. In general, fat replacement gave rise to intermediate crumb texture and structure properties in comparison with flour and sugar replacements. In vitro starch digestion showed that the flour‐replaced sponge cakes possessed the lowest hydrolysis index and glycaemic index values. The sponge cakes with the different replacements were well accepted by consumers, who expressed a high level of buying intention for all of them.     

制备工艺对果渣膳食纤维水合性质的影响

以桃渣和苹果渣为原料,研究湿法粉碎和干燥方式(热风干燥、微波干燥和真空干燥)对果渣膳食纤维的表观黏度和水合性质的影响。结果表明:料水比对果渣纤维溶液的黏度影响较大,黏度随着料水比的增大而显著增大;粉碎后,果渣的水合能力显著提高,粉碎时间对水合能力影响较显著,而料水比对果渣纤维的水合能力影响不明显(P>0.05);两种果渣的最合适粉碎时间为5min,A渣和B渣的最佳料水比分别为1:4和1:2。果渣纤维的真空干燥的效果优于微波干燥和热风干燥。     

Functional components of grape pomace: their composition,biological properties and potential applications

The roles of functional foods on human health have been realised by more and more researchers, food producers and consumers. Functional food ingredients from both plant and animal sources such as dietary fibre, soy protein isolate, whey protein isolate and omega 3 fatty acid have been widely used in functional food product development. Many fruit processing by‐products such as grape, apple and orange peels are rich in bioactive phytochemicals, dietary fibre and unsaturated fatty acids, hence have potential to serve as functional food ingredients. In this review, we summarise recent advancement of research in grape pomace (GP), the residual of grapes after wine making. The polyphenol profile of GP and their biological, antioxidant and antimicrobial activities, the stability of GP polyphenols in food system, the interaction between GP polyphenol and other food ingredients, as well as the functionalities of grape seed oil and GP fibre are covered.     

A comparative assess of high hydrostatic pressure and superfine grinding on physicochemical and antioxidant properties of grape pomace

In this study, we evaluate the effects of high hydrostatic pressure (HHP) and superfine grinding (SFG) treatment on grape pomace. The results showed that the HHP treatment improved physicochemical and antioxidant properties of grape pomace than the SFG treatment did. Moreover, the results of SEM indicated that the HHP‐treated grape pomace turned to have more lamellar structure, resulting in more hydrophilic groups exposed to improve WRC, WSC and SDF content. The results of FT‐IR spectra indicated that the main components and chemical structure of grape pomace after processing did not significantly change. Therefore, the HHP treatment had better effect in improving the functionality of grape pomace than that of the SFG treatment. The grape pomace treated by the appropriate processing methods could be used as functional foods.     

Association of physicochemical with technological properties of wheat

This study focused on twenty‐five different European common wheat varieties and aimed to identify correlations between the most important quality characteristics. When considering the physicochemical characteristics of the wheat samples, our results indicated that milling value is not correlated with vitreous kernel and test weight, but is correlated with gliadin/glutenin. The technological properties of the whole‐wheat flours estimated by means of Mixolab indicated rather good protein quality and the ability to form doughs with good stability in case of most of the samples. Technological behaviour of the flour was affected by dietary fibres and pentosan contents. The starch behaviour was positively correlated with the pentosan contents. The principal components analysis allowed establishing correlations between physicochemical, technological and nutritional parameters of wheat varieties. This finding is important for efficient selecting among wheat varieties, especially when healthy cereal‐based foods are desired.     

苹果渣可溶性膳食纤维提取工艺的研究

研究采用了酸性及碱性提取法从苹果渣中制备可溶性膳食纤维,利用正交试验设计确定了最佳提取工艺条件,提取酸溶性膳食纤维的最佳工艺条件是pH1.0、温度90℃、液料比15∶1(mL/g)、反应时间60min提取率为17.49%;碱溶性膳食纤维的最佳工艺条件是温度90℃、碱液浓度2.0%、反应时间60min、液料比2∶1(mL/g),提取率可达16.93%。     

高压均质和胶体磨改性对油橄榄果渣水不溶性膳食纤维性能的影响

采用高压均质和胶体磨改性处理油橄榄果渣水不溶性膳食纤维(IDF),比较改性前后IDF的微观形态、粒径分布、官能团组成及结晶结构,并测定分析其理化性质。结果表明:高压均质IDF的结构疏松,有较多的裂缝和空腔,平均粒径为66.97μm。胶体磨IDF的结构疏松,且部分出现断裂和破碎,平均粒径为79.52μm。高压均质和胶体磨改性处理均对IDF的官能团无影响,都具有糖类的特征吸收峰;对IDF的结晶结构和结晶度无影响,仍表现出纤维素I型的特征衍射峰。与未处理的IDF相比,高压均质IDF的持水力、膨胀力和持油力分别提高31.70%,78.87%,38.92%,对NO_2~-的吸附能力并无明显增加,对Cd~(2+)的吸附能力提高7.53%。胶体磨IDF的持水力、膨胀力和持油力分别提高19.93%,47.94%,32.97%,对NO_2~-的吸附能力增加8.20%,对Cd~(2+)的吸附能力并无明显增加。     

发酵法活化葡萄皮渣膳食纤维工艺的研究

以葡萄酒厂的副产物-葡萄皮渣为原料,采用嗜热链球菌和保加利亚乳杆菌混合发酵技术活化其中的膳食纤维,提高了葡萄皮渣中可溶性膳食纤维的含量。经正交试验得到乳酸菌发酵活化葡萄皮渣膳食纤维的最佳反应条件为：液料比10：1（v／w）,菌种比1：1（v／v）,发酵温度42℃,发酵时间12h,接种量10％,产品SDF含量为19．54％（干基）,较原料中SDF提高3．6倍。     

水浴和超声法制备苹果渣可溶性膳食纤维及其性能的研究

以苹果渣为原料,研究水浴法和超声法制备苹果渣可溶性膳食纤维及其性能。结果表明水浴法制备苹果渣可溶膳食纤维的适合工艺条件为:水浴温度80℃,水浴pH5,水浴料液比1∶20g/mL和水浴时间90min,在此条件下苹果渣SDF得率为12.76%;超声法制备苹果渣可溶膳食纤维的适合工艺条件为:超声温度60℃,超声pH5,超声料液比1∶20g/mL,超声时间45min和超声功率225W,在此条件下苹果渣SDF得率为14.14%。与水浴法相比超声法能加快苹果渣组织水解,扫描电镜分析表明超声对苹果渣纤维表面的微结构有破坏作用。在相同浓度下,苹果渣SDF抗氧化活性比苹果渣抗氧化活性高很多,但都远低于商业合成抗氧化BHA。      

Effects of mulberry pomace on physicochemical and textural properties of stirred-type flavored yogurt

Adding functional ingredients is an important method to develop functional dairy products. Mulberry pomace (MPo), a byproduct of mulberry fruit processing, is rich in phenolic compounds and anthocyanins and can be served as the functional ingredient in functional dairy products. The aim of this work was to prepare a functional flavored yogurt by incorporating MPo into stirred yogurt and to investigate the effects of MPo on the physicochemical and textural properties of the product during cold storage. We supplemented MPo powder up to 3% (wt/wt) in fermented milk, and the changes in color, pH, titratable acidity (TA), total phenol content (TPC), total anthocyanin content (TAC), water-holding capacity, rheological behavior, texture, and microstructure of the functional flavored yogurt were monitored during storage under 4°C for 28 d. The MPo powder brought a pink to dark red color to the yogurt, decreased the lightness (L*) and yellow-blue color (b*) values, increased the red-green color (a*) values, decreased the pH value, and increased the contents of TA, TPC, and TAC in a dose-dependent manner. The addition of MPo at 1%, 2%, and 3% (wt/wt) significantly increased water-holding capacity, consistency, viscosity, and viscosity index, and reduced firmness of yogurt samples. Supplementation of MPo significantly reduced the pore spaces and channels inside the samples and improved microstructure of the functional yogurt. During the 28 d of cold storage, MPo-fortified yogurt samples kept relatively constant color, although their L*, a*, and b* showed a decreasing tendency. The pH of all yogurt samples gradually decreased with increasing of TA. Interestingly, TPC and TAC contents and the texture parameters of MPo-fortified yogurt increased gradually and continuously during the 28 d of cold storage. Mulberry pomace is beneficial to improve the physicochemical and textural properties of yogurt and has the potential as a natural stabilizer to be used in functional yogurt rich in phytochemicals.     

Short communication: Compositional characteristics and aromatic profile of caciotta cheese obtained from Friesian cows fed with a dietary supplementation of dried grape pomace

The aim of the present work was to explore the chemical-sensorial characteristics and aromatic profile of caciotta cheese obtained from Friesian cows fed a diet enriched with grape pomace obtained from red grape (Vitis vinifera L.). Dietary enrichment with grape pomace influenced the production of caciotta cheeses in interesting ways from a compositional point of view, as cheese samples were rich in polyphenols, giving a high antioxidant potential. From a biochemical standpoint, we noted a slight decrease of proteolysis during ripening, whereas, according to the analysis of volatile compounds, lipolysis was the most relevant phenomenon in samples. The presence of bioactive compounds also modified the fatty acid profile of milk and cheese, leading to an increase in concentration of linoleic, vaccenic, and rumenic acids. No significant variations were found in the sensory profile. These results showed the potential of dietary grape pomace intake to influence the chemical-nutritional and nutraceutical properties of cow milk and cheeses, whose introduction to the market could be attractive to consumers, providing interesting implications for the dairy industry. Finally, our results identified of a valid use of an agro-industrial by-product, grape pomace, whose disposal generally presents economic and environmental problems.