Effects of benzylaminopurine on mango fruit ripening

The total and reducing sugars, organic acid and free amino acid contents of the edible portions of mango (cv. Boribo) were determined in unripe and ripe fruits, both treated and untreated with benzylaminopurine (BA).Total and reducing sugar contents were increased and organic acids and free amino acid contents were decreased after ripening in both cases. Benzylaminopurine delayed ripening and the composition of the ripe fruit was different from that of the untreated control.     

Chemical studies on the unripe and ripe fruits of Dennettia tripatela (pepper fruit)

The proximate composition, as well as some mineral, vitamin and anti-nutritional constituents in unripe and ripe fruits of Dennettia tripatela have been investigated. Moisture in the flesh of the fruit varied narrowly, ranging between 81% in the unripe and 82% in the ripe. The unripe and ripe seeds had about 25% and 71% lower moisture contents when compared with the unripe and ripe flesh, respectively. The crude protein and lipid contents in the unripe flesh were 4% DM and 2% DM, respectively; however, the corresponding values in the unripe seed represented 275% and 200% increases. Protein, lipid, fibre and ascorbic acid contents were generally higher in both the flesh and seed of ripe fruits. Tannin and oxalate contents in the flesh of ripe fruits represented about 100% and 50% increases, respectively, over corresponding values in the unripe fruit. The hydrocyanic acid contents tended to decrease from the flesh to the seeds and also from the unripe to the ripe fruits. The values for mineral contents varied widely, but calcium, magnesium and iron were present in appreciable quantities.     

Influence of processing on the generation of γ-aminobutyric acid in green coffee beans

A determination of the concentrations of free amino acids in differently processed green coffees indicated the nonprotein amino acid -aminobutyric acid (GABA), a well-known plant stress metabolite, to be present in raw coffee beans (Coffea arabica L.) in significantly varying amounts. The GABA content of unwashed Arabica beans (green coffee produced by the dry processing method) was always markedly higher than that of washed Arabicas (wet processing method) as well as that of untreated seeds. This result underlined the assumption that during postharvest treatment a significant metabolism occurs within coffee seeds. A putative relation between drought stress of the coffee seeds and postharvest treatment methods is discussed. The GABA content of green coffee beans may serve as a potent tool to characterize the type of postharvest treatment applied in coffee processing.     

Studies on nutritional requirements of the. latent phase of Ceratocystis paradoxa — the pineapple soft rot pathogen in Nigeria

The investigations on the nutritional requirements of the latent phase of Ceratocystis paradoxa causing ripe pineapple fruit rots were studied. The glucose, total protein and calcium ions levels were higher in ripe fruits than in unripe fruits. However, the ascorbic acid content was lower in the ripe fruits. All the carbon and nitrogenous compounds tested supported the growth of the fungus with D-glucose and casein hydrolysate providing the best carbon and nitrogenous sources respectively. The boiled extracts of unripe fruit rind at 60 °C and 80 °C were inhibitory to conidia germination. The carbohydrate and nitrogenous infusions at 1 % and 3 % induced unripe pineapple fruit rots of C. paradoxa. All the infusions at 10% concentrations were inhibitory to the development of the fungal pathogen.     

Correlation between cup quality and chemical attributes of Brazilian coffee

Brazilian arabica coffee is classified for trading according to the quality of the beverage obtained after roasting and brewing. In the present study, Brazilian green and roasted coffee beans were investigated for possible correlations between cup quality and the levels of sucrose, caffeine, trigonelline and chlorogenic acids, determined by HPLC analysis. Trigonelline and 3,4-dicaffeoylquinic acid levels in green and roasted coffee correlated strongly with high quality. To a lesser extent, caffeine levels were also associated with good quality. On the other hand, the amount of defective beans, the levels of caffeoylquinic acids (predominantly 5-caffeoyilquinic acid), feruloylquinic acids, and their oxidation products were associated with poor cup quality and with the Rio-off-flavor. The fact that similar correlations between cup quality and chemical attributes were observed in green and light roasted samples – the latter used for coffee cup classification – indicates that chemical analysis of green beans may be used as an additional tool for coffee quality evaluation.     

Analysis of phenolic compounds including tannins,gallotannins and flavanols of Uapaca kirkiana fruit

Tannins and phenolic acids were extracted from Uapaca kirkiana unripe pulp, seed coat, peel and embryo, as well as from ripe pulp, seed coat, embryo and peel portions of the fruit. Extraction was done using 50% methanol. More tannins were detected in the embryos of both ripe and raw fruit. Both ripe and raw seed coat contained the least amounts of tannins. The flavanoids and gallotannins also followed the same trend, with most of them in the embryos of both, the ripe and raw, fruit portions whilst the least were found in the seed coat. Tannins were, however lost during sun-drying compared to oven-drying, even though the differences were not very large. Also, raw fruits showed high concentrations of tannins compared to the ripe fruits. Hydroxybenzoic acid was found in the peel and pulp but none was detected in the seed coat or in the embryo. Similar phenolic acids were detected in the seed coat, except for caffeic acid and protocatechuic acid, detected in the embryo by both the UV florescence and Folin spray.     

Influence of the postharvest processing method on polysaccharides and coffee beverages

Fresh coffee fruits were subjected to different types of postharvest processing. Intact fruits were processed using the dry method (DI), peeled fruits were processed using the semi‐dry method (DP) and fruits were processed using the wet method (W). The extraction of polysaccharides from the seeds from the unprocessed and processed fruits indicated that arabinogalactans and (galacto)mannans were the main polysaccharides. Higher amounts of polysaccharides were extracted from processed coffee. Among the treatments, lower amounts of water‐soluble galactomannans were obtained from coffee beans processed by the dry and wet methods. The polysaccharides obtained from beverages prepared using beans from DI, DP and W methods showed different yields, total sugar and protein contents. Galactomannans and AGPs were also present in the coffee beverages. Although differences were found in the chemical compositions, no differences were observed in the viscosity or surface tension of coffee beverages from the DI, DP and W methods.     

Yeasts and lactic acid bacteria microbiota from masau (Ziziphus mauritiana) fruits and their fermented fruit pulp in Zimbabwe

Masau are Zimbabwean wild fruits, which are usually eaten raw and/ or processed into products such as porridge, traditional cakes, mahewu and jam. Yeasts, yeast-like fungi, and lactic acid bacteria present on the unripe, ripe and dried fruits, and in the fermented masau fruits collected from Muzarabani district in Zimbabwe were isolated and identified using physiological and molecular methods. The predominant species were identified as Saccharomyces cerevisiae, Issatchenkia orientalis, Pichia fabianii and Aureobasidium pullulans. A. pullulans was the dominant species on the unripe fruits but was not isolated from the fermented fruit pulp. S. cerevisiae and I. orientalis were predominant in the fermented fruit pulp but were not detected in the unripe fruits. S. cerevisiae, I. orientalis, P. fabianii and S. fibuligera are fermentative yeasts and these might be used in the future development of starter cultures to produce better quality fermented products from masau fruit. Lactic acid bacteria were preliminary identified and the predominant strains found were Lactobacillus agilis and L. plantarum. Other species identified included L. bifermentans, L. minor, L. divergens, L. confusus, L. hilgardii, L. fructosus, L. fermentum and Streptococcus spp. Some of the strains of LAB could also potentially be used in a mixed-starter culture with yeasts and might contribute positively in the production of fermented masau fruit products.     

Volatile constituents of unripe and ripe kundang fruits (Bouea macrophylla Griffith)

Kundang, a seasonal, tropical fruit is consumed either as raw (unripe) or ripe in south-east Asia. Investigations performed by using gas chromatography-mass spectrometry revealed volatile constituent compounds in ripe fruits to be much higher than unripe fruits. Nearly 82 compounds (comprising 99.96% of the total volatiles) and 121 compounds (encompassing 97.33% of the total volatiles) were identified in unripe and ripe fruits, respectively. Results generated is envisaged to enhance the existing database on tropical fruits volatile profiles, as well as benefit local food industries (to exploit the unique fragrance character impact compounds for aroma essence production) for commercial usage.     

Polyphenoloxidase Activity, Polyphenols Concentration and Browning Intensity during Soursop (Annona muricata, L.) Maturation

Values for polyphenoloxidase (PPO), total phenols and ascorbic acid, browning intensity and pH in soursops (Annona muricata, L.) decreased during maturation. Optimum pH was 7.5 (fully developed immature, mature unripe and ripe fruits) or 7.0 (fully ripe fruits). High correlation was found between PPO activity and phenolic compounds. The enzymic browning of soursops occurred during maturation. The least browning intensity was in fully ripe fruits.     

Contribution of amino acids to strawberry fruit quality and their relevance as stress indicators under NaCl salinity

Strawberry cvs Korona and Elsanta, differing in their sensitivity to salt stress, were exposed to 0, 40, or 80 mM NaCl in the root medium from the end of April to mid-August. Although fruits of both cultivars contained comparable amounts of Na⁺ and Cl⁻, fruit quality was more impaired in cv. Elsanta, as indicated by the larger reductions of fruit size and sugar/acid ratios. Malondialdehyde levels started to rise significantly at 40 mM NaCl in the more sensitive cv. Elsanta, but at 80 mM in cv. Korona. Total amino acid levels, especially contents of essential amino acids, rose significantly in both cvs. Salt stress also increased contents of free proline, asparagine, and glutamine. Their increases may contribute to osmotic adjustment. The results of the present study favour the interpretation that elevated levels of proline, asparagine and glutamine are indicative of salt stress damage.     

Physicochemical characteristics of green coffee: comparison of graded and defective beans

ABSTRACT:  Defective (triage) coffee beans are beans rejected after separating the graded ones according to the size and color. These coffee beans represent about 15% to 20% of coffee production in India but are not utilized for beverages since these affect the quality of coffee brew. In the present study, physical characteristics such as bean density, brightness, titratable acidity, pH, moisture, and total soluble solids and also chemical composition, namely, caffeine, chlorogenic acids, lipids, sucrose, total polyphenols, and proteins, were evaluated in defective as well as in graded green coffee beans. The physical parameters such as weight, density, and brightness of defective coffee beans were low compared to the graded beans, which is due to the presence of immature, broken, bleached, and black beans. Caffeine content was low in triage beans compared to graded beans. Chlorogenic acids, one of the composition in coffee responsible for antioxidant activity, was found to be intact (marginally high in some cases) in defective coffee beans. Hence, triage coffee beans can be evaluated as a source of antioxidant or radical scavenging conserve for food systems.     

不同初加工工艺对云南阿拉比卡咖啡品质的影响

为了挖掘优质的云南精品咖啡,以云南普文南岛河卡蒂姆系列品种、成熟全红果为试材,探索带果胶非浸泡式发酵(鲜果发酵和水洗干发酵、日晒、黑蜜、干红蜜)和浸泡式发酵(三重水洗发酵、全水洗)等六种不同初加工工艺对生豆粗蛋白质、粗脂肪、咖啡因等内含物质及密度的影响,并采用模糊数学法对熟豆感官风味进行统计学分析。感官评审结果表明:采用黑蜜加工处理和日晒加工处理的咖啡感官品质最佳,综合评分为5.49和5.44,评定为"优";采用三重水洗发酵处理的咖啡豆感官品质最差,综合评分为3.37,评定为"中";干红蜜加工处理的咖啡感官品质综合评分为3.85,评定为"良好";鲜果发酵和水洗干发酵、全水洗发酵加工感官品质综合评分为3.72,3.70,评定为"良"。理化检测结果:带果胶非浸泡式发酵的四种加工方式所得咖啡生豆的粗蛋白质、粗脂肪、咖啡因含量高于两种浸泡式发酵加工所得咖啡生豆;不同的初加工工艺对咖啡生豆密度的影响差异不显著。     

Discrimination between immature and mature green coffees by attenuated total reflectance and diffuse reflectance Fourier transform infrared spectroscopy

The objective of this work was to evaluate the potential of Fourier transform infrared spectroscopy (FTIR) in the characterization and discrimination between immature and mature or ripe coffee beans. Arabica coffee beans were submitted to FTIR analysis by reflectance readings employing attenuated total reflectance (ATR) and diffuse reflectance (DR) accessories. The obtained spectra were similar, but in general higher absorbance values were observed for nondefective beans in comparison to immature ones. Multivariate statistical analysis (principal component analysis, PCA, and agglomerative hierarchical clustering, AHC) was performed in order to verify the possibility of discrimination between immature and mature coffee samples. A clear separation between immature and mature coffees was observed based on AHC and PCA analyses of the normalized spectra obtained by employing both ATR and DR accessories. Linear discriminant analysis was employed for developing classification models, with recognition and prediction abilities of 100%. Such results showed that FTIR analysis presents potential for the development of a simple routine methodology for separation of immature and mature coffee beans. Practical Application: The ultimate goal of this research is to be able to propose improvements in the way immature coffee beans are separated from graded mature beans in coffee facilities (cooperatives and other coffee producer's associations). The results obtained herein point toward FTIR as a potential tool for the aimed improvements.     

Chemical Evaluation of Musa ‘Bhimkol’ as a Baby Food

The edible pulp of Musa ‘Bhimkol’ was analysed for certain organic compounds and mineral nutrients at two stages of development of the fruit to evaluate it as a baby food. Energy value and carbohydrate concentration increased substantially as the fruit ripened so that 16.8% of the energy requirement (recommended daily allowance, RDA) for six-month-old infants would be met by 100 g of the fresh pulp. Although vitamin C content decreased at maturation, 7% of the RDA would be provided by 100 g fresh pulp. The fruit was found to be very rich in macro- and micronutrients, and 100% of the six-month infants RDA for K, Mn, Zn and Se would be satisfied with 100 g of fresh pulp. This amount of pulp would also provide 86%, 57%, 24% and 12% respectively of the Mg, Cu, Fe and P RDA. P and Mg were found to be more highly concentrated in the ripe than in the unripe fruit whereas the reverse was the case for Ca and Se. Aspartic acid, glutamic acid and leucine were the major amino acids in the ripe fruit and respectively constituted 13.1, 12.5 and 7.9%, of the total. The concentration of essential and non-essential amino acids was much higher than that in a commercial banana. Twelve of the 17 amino acids analysed were more concentrated in the mature compared with the green fruit, and 11 of these were an order of magnitude higher than in M paradisiaca L banana. The results of the present study demonstrate that Musa ‘Bhimkol’ is a nutritious baby food.     

Discrimination between defective and non-defective Brazilian coffee beans by their volatile profile

The coffee roasted in Brazil is considered to be of low quality, due to the presence of defective coffee beans that depreciate the beverage quality. In view of the fact that coffee flavour is directly related to the volatile compounds produced during roasting, the objective of the present study was to perform a comparative evaluation of the volatile fraction of defective (black, immature, sour) and healthy coffee beans, in order to find possible chemical markers for detection of defective coffee beans in roasted coffee. Volatiles extraction and concentration was performed by solid phase micro-extraction (SPME) of the roasted coffee headspace, using a triple phase (divinylbenzene/carboxen/polydimethylsiloxane) fiber. Analysis of the volatile profiles was performed by GC–MS. The results obtained showed that the proposed methodology was adequate for extraction, concentration and analysis of the coffees volatile profile. Several substances were identified as possible markers for differentiating black, sour and immature beans from healthy coffee beans. Statistical analysis of the data by principal components (PCA) demonstrated that the volatile profile enables the differentiation of healthy and defective coffees. The data were separated into two major groups, one represented by immature and black beans and the other by healthy and sour coffee beans. Such results indicated that black and sour beans can be associated to fermentation of immature and of healthy beans, respectively.     

Assessment of green coffee bean metabolites dependent on coffee quality using a 1H NMR-based metabolomics approach

There is increasing interest in the coffee grade or quality with the rise of coffee consumption, but a classical, chemical analysis-based understanding of the coffee bean grade is still limited. We therefore report the identification of green coffee bean metabolites related to coffee bean quality using a ¹H NMR-based metabolomic analysis of well-established specialty-grade green coffee beans, in particular, of a single species (Coffea arabica). The higher levels of sucrose and the lower levels of γ-aminobutyric acid (GABA), quinic acid, choline, acetic acid and fatty acids observed in specialty or high-grade green coffee beans, compared to commercial-grade beans, were suggestive to be multiple markers for characterizing specialty green coffee bean. In particular, variations in sucrose and GABA levels between specialty and commercial coffees could be a consequence of different environmental conditions, for example, biotic or abiotc stresses, at growing regions. These results highlight an alternative method of metabolomic approach for grading green coffee bean.     

Influence of environmental factors,wet processing and their interactions on the biochemical composition of green Arabica coffee beans

Although cultivation of Arabica coffee trees at high elevation is known to favourably affect the final quality of the beverage, quantitative data describing the influence of climatic conditions on the chemical composition of the seed are still lacking. Similarly, post-harvest treatments of the beans are known to affect the generation of flavour, but the chemical transformations that occur during wet processing are poorly understood. To better characterise the effects of the environment, wet processing and their possible interactions, we quantified the changes in the main chemical components of the coffee seed (lipids, chlorogenic acids, sugars and caffeine) caused by wet processing, and analysed how these changes were affected by the variations induced by the environment before harvest. Using 16 experimental plots in Reunion Island displaying broad climatic variations, we showed that chlorogenic acids and fatty acids in the seed were controlled by the mean air temperature during seed development. By contrast, total lipid, total soluble sugar, total polysaccharide and total chlorogenic acid contents were not influenced by climate. Glucose content was positively affected by altitude, while sorbitol content after wet processing depended directly on the glucose content in fresh seeds.     

Nonenzymic browning. XII. Maillard reactions in green coffee beans on storage.

During storage of green coffee beans at increased temperature and at constant humidity reducing sugars present in original beans react with free amino acids with formation of colourless unstable products. Additional reducing sugars and free amino acids are produced by hydrolysis of polysaccharides and proteins, respectively. The second stage of storage is characterized by only slight changes in the content of free amino acids and sugars but by intensive browning reactions. This latter stage was characterized by deterioration of sensory quality of coffee beverage, especially of its odour. Lysine combined in protein was involved in browning reactions via colourless intermediary products.     

枣果中酚类物质的高效液相色谱分析

建立了一种可同时测定11种酚类物质的高效液相色谱(HPLC)法,并对枣果中的酚类物质进行了分析测定。色谱条件为:Waters Symmetry C_(18)柱(4.6 mm×150 mm,5μm),流动相为甲醇和磷酸水(pH 2.6),280 nm和320 nm双波长紫外检测,柱温30℃,进样量5μL,流速0.6 mL/min,梯度洗脱程序:0 min 15%A,15～25 min 25%A,65 min 75%A,70 min 15%A,梯度线性变化。经测定,新鲜梨枣果内中含有儿茶素、表儿茶素、没食子酸、原儿茶酸、绿原酸和芦丁等酚类物质,其中儿茶素和表儿茶素占检测到的酚类物质总量的85%以上,未成熟果含量远高于成熟果。