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91.
采用反相高效液相色谱法、2,4-二硝基苯肼法对300～600 MPa处理15 min的黑莓汁中有机酸、VC进行检测分析,并采用DPPH.法对其协同抗氧化性进行评价。结果表明:黑莓汁有机酸主要是L-苹果酸,占总酸的87.98%,并含有少量的α-酮戊二酸、醋酸、柠檬酸和琥珀酸等;超高压处理对黑莓汁中琥珀酸和L-苹果酸的影响显著(P<0.05),对其他酸作用不显著(P>0.05)。经300 MPa、15 min处理,黑莓汁中L-苹果酸含量减少12.2%,400、500和600 MPa处理15min后,其L-苹果酸含量分别增加8.53%、6.08%和22.35%;超高压黑莓汁中VC的保留率在90.10%～97.92%;随着L-苹果酸浓度的增加,其协同VC清除DPPH自由基能力显著增强(P<0.05),表明L-苹果酸可协同VC增加其抗氧化性。 相似文献
92.
采用单因素和L9(34)正交试验研究皂土用量、搅拌速度和作用时间对黑莓果酒的澄清效果的影响,以果酒澄清度和色度为考核指标确定皂土澄清处理条件,并通过测定皂土澄清处理前后黑莓果酒中主要成分含量的变化和热稳定性变化,研究皂土对黑莓果酒的澄清作用.研究结果表明,皂土用量为0.6g/L、搅拌速度为30r/min、作用时间为72h为最佳处理条件.在此条件下,皂土处理后,果酒中溶性固形物、总糖、总酸度、有效酸度等有很小的变化,总酚含量下降7.04％,蛋白质含量下降62.4％.澄清处理之后,热稳定性有较大提高.70℃条件下热处理仍能保持稳定.说明皂土是一种良好有效的黑莓果酒澄清剂. 相似文献
93.
目的提高黑莓籽出油率及品质,增加黑莓附加值。方法以黑莓籽为原料,冷冻干燥脱水、冷冻粉碎细化、超临界CO2流体提取黑莓籽油。考察了CO2流量、提取压力、提取温度、提取时间、分离温度和分离压力对黑莓籽出油率的影响,并通过响应面试验确定了超临界CO2提取黑莓籽油的最佳工艺条件。结果超临界CO2提取黑莓籽油的最佳工艺参数为:将黑莓籽经冷冻干燥至含水量3.43%~5.35%,冷冻粉碎过60目筛,选用超临界CO2流体提取压力30 MPa,温度40℃,CO2流量25 L/h,提取时间60 min,分离压力7 MPa,分离温度35℃。在此条件下,出油率达到18.6%。结论此工艺提取的黑莓籽油品质优良,绿色环保。 相似文献
94.
采用Folin-Ciocalteu法测定黑莓提取液中总多酚含量,确定以没食子酸为标准的最佳测定条件。结果表明:在5 mL的反应体系中,吸取0.5 mL样品,先加入2.5 mL 0.1 mol/L Folin-Ciocaltou试剂振荡后,再加入2 mL 7.5%Na2CO3溶液,摇匀,25℃显色120 min,在765 nm波长下测定吸光度,没食子酸浓度在5 mg/L~60 mg/L范围内与吸光度存在较好的线性关系。此方法操作简单、稳定性及结果重现性好。利用Folin-Ciocalteu法测定黑莓样品液中没食子酸的平均添加回收率达到100.2%,RSD为1.40%。 相似文献
95.
The estimation of ripeness is a significant section of quality determination since maturity at harvest can affect sensory and storage properties of fruits. A possible tactic for defining the grade of ripeness is sensing the aromatic volatiles released by fruit using electronic nose (e‐nose). For detection of the five ripeness grades of berries (whiteberry and blackberry), the e‐nose machine was designed and fabricated. Artificial neural networks (ANN), principal components analysis (PCA), and linear discriminant analysis (LDA) were applied for pattern recognition of array sensors. The best structure (10–11‐5) can classify the samples in five classes in ANN analysis with a precision of 100% and 88.3% for blackberry and whiteberry, respectively. Also, PCA analysis characterized 97% and 93% variance in the blackberry and whiteberry, respectively. The least correct classification for whiteberry was observed in the LDA method. 相似文献
96.
This research examines the impact of various pretreatments on effective moisture diffusivity coefficient (Deff), activation energy (Ea), specific energy consumption (SEC), color, and shrinkage of blackberry (Rubus spp.). Hot air drying experiments were conducted under three different temperatures (50, 60, and 70°C) and four pretreatments, including thermal pretreatment by hot water blanching at 70, 80, and 90°C, pulse pretreatment with microwave having power of 90, 180, and 360 W, chemical pretreatment using ascorbic acid (1% in distilled water), and mechanical pretreatment using ultrasonic vibration with working frequency of 28 ± 5% kHz for 15, 30, and 45 min. The results show that the highest Deff value, which was 1.00 × 10–8 m2/s, could be achieved by using a microwave pretreatment with power and drying temperature of 360 W and 70°C͘, respectively. Moreover, the lowest Deff value obtained from this similar pretreatment condition was 3.10 × 10–9 m2/s at a drying temperature of 50°C, while Ea ranged from 13.61 to 26.02 kJ/mol. The highest and lowest SECs were 269.91 kW hr/kg for the control sample and 75.63 kW hr/kg for the microwave pretreatment, respectively. Furthermore, the largest color change and shrinkage were detected in ascorbic acid pretreatment and control sample, respectively. 相似文献
97.
黑莓汁加工会产生大量的废弃物黑莓渣,黑莓渣富含多酚类生物活性物质。黑莓渣中总酚含量(以干基计)为6.86%(w/w),花色苷含量(以干基计)为0.38%(w/w)。从黑莓渣中提取多酚和花色苷的研究结果表明,花色苷的最佳提取工艺条件是:以80目的黑莓渣粉为原料,采用含有1%柠檬酸的50%乙醇溶液为提取剂,在35℃提取2次,每次30min、料液比为1∶10。花色苷的提取率为98.33%。总酚的最佳提取工艺条件是:以80目的黑莓渣粉为原料,用含有1%柠檬酸的50%乙醇溶液为提取剂,在55℃提取2次,每次15min、料液比为1∶10,在此条件下总酚的提取率为93.72%。 相似文献
98.
选取果胶酶酶解黑莓浆加酶量、酶解温度和酶解时间3 个因素进行Box-Behnken 设计,利用响应面法对其提取工艺进行优化研究。利用Design Expert 软件,对酶解花色苷产量的二次多项数学模型解逆矩阵分析表明：在加酶量0.21%、酶解时间1.46h、酶解温度42.7℃工艺条件下,酶解黑莓汁里花色苷产量最高,其最大提取产量预测值为0.645mg/g,与实测值相符。对花色苷含量、Hunter 颜色值(L*、C*、h)进行两两线性相关分析,相关程度表明,C* 值可在一定程度上表征花色苷含量。 相似文献
99.
“三冠王”黑莓果实分别用5μg/L 1-MCP 和真空预冷(10℃)处理,然后于0℃贮藏21d,并测定黑莓果实的贮藏效果及活性氧代谢。1-MCP 和真空预冷处理均抑制黑莓果实色泽L*、a*、b* 值和可溶性固形物的升高,其中真空预冷作用效果优于1-MCP。虽然1-MCP 和真空预冷处理均推迟了LOX 活性、花青素含量的上升,但1-MCP 处理还具有降低膜脂过氧化产物MDA 的积累和对总还原能力的推迟作用,而真空预冷处理能够提高总还原能力,但也诱导MDA 含量升高。结果表明1-MCP 和真空预冷处理均可有效延缓黑莓果实的品质劣变,但对活性氧代谢的影响出现明显差异。 相似文献
100.