Experimental Study and Thermal Modelling of Cocoa Shell Convective Drying in an Indirect Solar Dryer

The concern of the present work is the convective drying of empty cocoa shells in an indirect solar dryer. Some drying experiments, using one sample, were carried out. During the experiments, the sample is introduced in the drying chamber. Then at steady time intervals, the sample is withdrawn from the drying chamber, for a rapid weighing. After each weighing, the sample is reintroduced in the dryer. At each time interval, the ambient temperature of the drying chamber and its relative humidity γ are measured by a thermo-hygrometer. From the experimental data, a theoretical determination of the moisture evaporated from the product was performed and a good agreement was found between the theoretical and experimental values, confirmed by the value of the RMSE. Those calculations used the constants in the Nusselt number found in literature. Then those constants were evaluated again, to get new values more suitable with the experimental data. The dimensionless numbers of Nusselt, Grashof and Prandtl were calculated. That allowed the calculation of the average value of the Nusselt number. The average convective heat transfer coefficient was determined.

Comparative Effects of Organic Cocoa Shell-Based and Inorganic NPK Fertilization on the Growth and Yield of Four Cassava Varieties

Looking of finding an alternative to the use of chemical fertilizers to increase yields of cassava (Manihot esculenta), trials were carried out in the Lamto zone in central Côte d’Ivoire. Thus, the effects of compost and ash from cocoa shell and NPK were tested on the agronomic parameters of cassava. The trial was conducted for two years with four varieties of cassava: Yacé, Alleda agba, Six mois and Bonoua, grown on elementary plots treated with one of these fertilizers. The experimental design was complete randomized blocks with three replicates. Analysis of the results showed that the Six mois variety gave the longest stems (131, 67 cm) with the cocoa shell compost. The Bonoua variety, on the other hand, gave the largest diameter of the stem base (21.56 mm), a higher number of leaves (77.30) and a large wingspan (136.89 cm) with cocoa shell compost. The leaves developed by the plants of this variety were wider (19.30 cm) and longer (17.96 cm) with cocoa shell compost. Also, this Bonoua variety treated with shell compost yielded a high number of tuberized roots (5.11), high average weight per plant (5.83 kg/plant) and higher yield (58.29 t/ha). This compost of cocoa shell has also allowed a better conservation of the cultivated soils quality.

Natural Solar Drying and Charcoal Production by Pyrolysis of Empty Shells of Cocoa Pods Using a Carbonisation Stove Fitted with a Chimney

The world’s production of cocoa highly has grown since 1960.In West Africa,the production reached about 3,000,000 tons in 2012.More than 50%of the world’s production of cocoa comes nowadays from Côte d’Ivoire and Ghana and Côte d’Ivoire is the biggest producer.After harvesting,the empty shells,considered as non-useful wastes,are abandoned in the fields where they become a source of pollution.That yields millions of tons of biomass that can be converted into charcoal,instead of being sources of pollution.In the present work,the drying kinetics of the empty wet shells were studied.Then,charcoal production by pyrolysis of those empty shells of cocoa pods was performed,using a carbonisation stove fitted with a chimney.The study showed that the empty shells have a high moisture content.The different phases of the drying were observed.The study compared the drying rates and the diffusion coefficients of a small sample and a big sample.Two experiences of carbonisation of the empty shells were successfully carried out.For the first experiment,the pyrolysis temperatures were recorded and the charcoal mass efficiency calculated.For the second experiment,the temperatures were higher and the result was colored charcoals.The colorations disappeared after some hours.

Enhancement of <i>Theobroma cacao</i>Seedling Growth and Tolerance to <i>Phytophthora megakarya</i>by Heat-Treated Oyster Shell Powder

The aim of this study was to evaluate the ability of oyster shell powder soil amendment to enhance cocoa seedling growth and induce resistance against Phytophthora megakarya in nurseries. The results showed that heat-treated oyster shells powder at 1% (w/w) soil amendment significantly increased plant height, leaf number, leaf area, dry shoot and root weight more than chemical fungicide and control treatment after twelve weeks of growth. The results showed that heat-treated oyster shell powder raised soil pH significantly and reduced P. megakarya load of the soil suspension by 82%. Assessment of resistance stimulation by leaf inoculation showed the highest level of resistance recorded in plants treated either with heat-treated or non-treated oyster shell powder. Furthermore, total phenolic compounds contents, total soluble proteins contents, polyphenoloxidase, chitinase, peroxidase and β-1,3-glucanases activities increased in both healthy or infected leaves from cacao plants treated with oyster shell powder more than those treated with chemical fungicide. These findings demonstrated that heat-treated oyster shell powder could be used as biofertilizer and biofungicide to improve the quality of cocoa seedling production and protect the plant against P. megakarya.

可可壳酊剂香味成分分析研究

采用涡旋萃取法提取可可壳酊剂的香味成分,利用气相色谱-质谱分析分析其中的香味成分,并用面积归一化法测定了各种成分的质量分数。结果表明:可可壳酊剂中共鉴定出54种香味成分,其中咖啡因、乳酸乙酯、可可碱、苯乙酸乙酯、琥珀酸单乙酯占比分别为51.54%、9.42%、6.70%、4.64%、3.28%,构成了可可壳酊剂的主要香味成分,可可壳酊剂在卷烟中使用具有丰富卷烟可可香和烘烤香,掩盖杂气,降低烟气刺激性,提升烟气浓度的作用。

高效液相色谱法测定可可粉中可可壳含量

建立了固相萃取-高效液相色谱法测定可可粉及可可壳中2种脂肪酸色酰胺成分(二十二烷酸色酰胺和二十四烷酸色酰胺)的定量分析方法,根据2种物质在可可粉和可可壳中的含量差异进行可可粉中可可壳含量的测定。样品经过三氯甲烷涡旋振荡加超声提取,硅胶固相萃取柱净化,采用Venusil C18色谱柱,乙腈+四氢呋喃+水为流动相,荧光检测器检测。在上述条件下,2种脂肪酸色酰胺在50～1 000μg/L范围内线性关系良好(r> 0. 999 1),方法的检出限和定量限分别为0. 03 mg/kg和0. 1 mg/kg,加标回收率在92%～103%之间,相对标准偏差为2. 1%～6. 2%。利用可可粉中脂肪酸色酰胺含量与掺入的可可壳含量之间的线性关系,建立了计算可可粉中可可壳含量的简单定量分析模型,模拟样品和实际样品的验证结果表明,该模型的预测值与实际值有着较好的一致性,对可可粉中混入量5%及5%以上(质量分数)的可可壳可予以较好鉴定。

可可粉、可可壳的致香成分分析及卷烟应用效果比较

为比较可可粉、可可壳的致香成分及应用效果差异,对已烘焙的可可豆按部位进行酊剂的制备,得到可可粉酊与可可壳酊,利用气相色谱-质谱联用方法(GC-MS)分析两种酊剂的挥发性致香成分,并应用于卷烟对比应用效果。结果显示:(1)对可可粉酊和可可壳酊分别鉴定出38种和36种挥发性致香成分,其中共有成分29种,含量较高的主要为可可碱和咖啡因;可可粉酊独有的化学成分9种,香气表现为奶香、酸香、烘烤香、蜜甜香;可可壳酊独有的化学成分7种,香气表现为焦香、木香、坚果香、烘烤香;(2)将可可粉酊和可可壳酊应用于"椰树"空白烟丝中,添加质量分数0.3%时应用效果最佳,可可粉酊主要赋予卷烟可可特征香气,可可壳酊主要赋予卷烟烘烤香和坚果香。因此在实际操作中,可根据调香应用的实际需求进行选择。

高效液相色谱法测定可可粉和可可壳酊中的可可碱和咖啡因

采用高效液相色谱法测定可可粉和可可壳酊中的可可碱及咖啡因含量 ,固定相为Hyper silODS ,流动相为甲醇 -醋酸 -水 (2 0∶1∶79) ,紫外检测波长 2 75nm。样品中可可碱和咖啡因的回收率分别为 98.6 %± 0 .71%和 97.1%± 0 .80 % ,变异系数为 0 .80和 1.4 9。

基于UPLC-Q-TOF MS/MS技术的可可粉中掺入可可壳定量检测方法研究

本研究基于超高效液相色谱-四极杆-飞行时间串联质谱(UPLC-Q-TOF MS/MS)技术,结合主成分分析和正交偏最小二乘法-判别分析等多元统计分析,以厄瓜多尔产地可可豆为研究对象,筛选和鉴定可可壳的特征标志物,并利用该特征标志物实现可可粉中可可壳掺入量的定量检测。结果表明,可可粉与可可壳的组分具有较大差异。可可壳的特征标志物为苦木内酯Ⅰ;当可可粉中掺入可可壳的量在1%~50%范围内时,苦木内酯Ⅰ的峰面积与可可壳掺入量之间存在良好的线性关系(相关系数R^(2)>0.999 9),方法的检出限和定量限分别为0.3%和1%。使用该方法进行盲样验证发现,检测含量和实际掺入量基本一致,并对市售样品进行检测,可可壳含量在2.51%~9.03%之间。本方法具有较高的准确性和灵敏度,可用于市售可可粉的掺假鉴别。

双离子液体修饰硅胶材料对可可壳萃取液中茶多酚的吸附研究

茶多酚作为一种具有抗氧化抗癌活性的天然物质,受到广泛关注。可可壳萃取液中含有大量的茶多酚,利用吸附剂将其从萃取液中吸附分离是最为便捷的方法。双离子液体修饰吸附剂具有多种优良的性能,能通过产生多种化学键对目标物进行高效吸附。为了揭示双离子液体官能团与茶多酚之间吸附机理,以硅胶材料为基体,通过硅烷化试剂对其改性后再修饰双离子液体,获得了12种修饰硅胶材料,而后在不同温度条件下对多个浓度的茶多酚标准溶液进行静态吸附研究。结果表明,修饰后的材料在1568.7cm-1附近出现了新的峰,这是咪唑基团的特征吸收波长,说明咪唑基团被修饰在硅胶材料上。在2936.4cm-1附近出现了吸收峰,这个波长在C--H烷基基团的吸收波长范围内,因此说明了双离子液体基团被修饰在硅胶材料上;Sil@Eim-IL(IL为Bim、Eim、Mim、Im)系列的4种材料对茶多酚的吸附量远高于其他系列,吸附量在57.3mg/g以上;30℃下2h为最优化的吸附条件,Sil@Eim-Eim比其他吸附剂具有更高的吸附量,达到58.0mg/g;在最优条件下,利用Sil@Eim-Eim对可可壳甲醇水萃取液中茶多酚进行吸附分离,经高效液相色谱分析证明其能够完全吸附萃取液中的茶多酚。

Biogas Production from Various Typical Organic Wastes Generated in the Region of Cantabria (Spain): Methane Yields and Co-Digestion Tests

Batch trials were carried out to determine the methane potential yields of some typical organic wastes generated in the region of Cantabria (Spain): cocoa shell, cheese whey and sludges from dairy industry. Anaerobic co-digestion trials of these wastes with dairy manure were also investigated in batch at 35℃. Cheese whey obtained similar methane yields than dairy manure, between 17.5 and 19.3 L CH4kg-1 cheese whey compared with 18.0 L CH4kg-1 manure. Methane yields of various sludge samples collected from wastewater treatment facilities of dairy industries were influenced by its origin. Sludge samples from fat separation devices were the most productive in terms of specific methane yields compared with biological sludge from an aerobic reactor. Sludge samples from fat separator reached specific methane productivities of 350 and 388 L CH4kg-1 VS (10.5 and 24.1 L CH4kg-1 sludge), whereas biological sludge yielded 125 L CH4kg-1 VS (12.6 L CH4kg-1 sludge). The methane potential of sludge samples was influenced by solids content. Cocoa shell resulted to be an interesting waste for anaerobic digestion due to its high VS content, yielding 195 L CH4kg-1 cocoa shell. It is a waste that can considerably improve methane yields in anaerobic co-digestion with dairy manure. However, at proportions of 10% cocoa shell, the process was hindered by hydrolysis of particulate matter. Anaerobic digestion at higher temperatures (thermophilic range) could be a better option for this kind of waste. Co-digestion of 5% cocoa shell with 35% dairy sludge and 60% dairy manure resulted in 80.5% higher methane production compared to anaerobic digestion of dairy manure alone.