OPTIMIZATION STUDY FOR THE PRODUCTION OF CITRIC AND GLUCONIC ACID FROM FIG WATER EXTRACT BY ASPERGILLUS NIGER IN SURFACE FERMENTATION

The production of citric and gluconic acid from fig extract by Aspergillus niger ATCC 10577 and A. niger B60 in surface fermentation was investigated. The strain 10577 gave higher concentration of citric and gluconic acid than strain B60. A maximum citric and gluconic acid concentration (20.5 and 97.0 g/L, respectively), citric acid yield (12%), biomass dry weight (18.5 g/L), and sugar utilization (85%) was achieved at an initial sugar concentration of 200 g/L and a pH of 7.0. On the other hand, the highest gluconic acid yield (79.7%) was obtained in culture grown at initial sugar concentration 100 g/L. The addition of 4% (v/v) methanol in the fig extract increased the concentration of citric and gluconic acid from 20.5 and 97.0 g/L to 30.7 and 145.5 g/L, respectively. Citric acid was separated from the gluconic acid by extraction with diethyl ether or ethyl acetate.     

PRODUCTION AND CHARACTERIZATION OF THE CASHEW APPLE (ANACARDIUM OCCIDENTALE L.) AND GUAVA (PSIDIUM GUAJAVA L.) FRUIT POWDERS

Cashew apple and guava residues from fruit juice processing industry were prepared as dehydrated fruit powders. Differences in compositional and physicochemical characteristics between both fruit powders were significant at the 5% probability level, with exception to ash content. It is important to point out that despite the dehydration process, both samples can still be considered good sources of vitamin C. In addition, the results show that the guava and cashew apple powders may be useful in the food industry as high dietary "fiber ingredients." Higher lipid (14.05%) content was observed in guava powder. The guava powder could be an alternative source of lipid. The data also indicated that these materials are good sources of ash. The results suggest further utilization of these residues as valuable food ingredients or as a resource for nutraceuticals.

PRACTICAL APPLICATIONS

Large quantity of agro-industrial residues formed by fruit juice extraction represents a major disposal problem. An alternative to recycling the fruit-industrial residue is to submit it to drying processes and transform into value-added products as dehydrated fruit powder. In this way, this process contributes to diminish the problem and to recover valuable biomass and nutrients. The purpose of this study was to develop a technology to obtain guava and cashew apple powders with the objective of finding alternatives to the exploitation of these residues as valuable sources of vitamin C, as ashes and lipid that should also be regarded as potential nutraceutical resources in future or functional ingredients.     

超声辅助提取荠菜中总生物碱的工艺研究

研究了以乙醇为溶剂超声辅助提取荠菜中总生物碱的工艺。首先通过预试验确定荠菜中生物碱的存在，然后通过单因素和正交实验设计考察各因素对荠菜总生物碱提取率的影响。实验结果表明：70％乙醇为提取溶剂，料液比（原料质量：乙醇体积）为1：10，水浴温度70℃，超声提取20min，再重复浸泡、超声提取1次，加酸浸泡时间为30min，原料粉无需脱色处理，在此条件下荠菜中总生物碱的提取效果最好。     

THE USE OF PULSED ELECTRIC FIELDS IN PRODUCING JUICE FROM PAPRIKA (CAPSICUM ANNUUM L.)

Investigations were conducted on the impact of pulsed electric field (PEF) treatment on yield and some quality parameters of juice from paprika and results were compared to the results of juice obtained from enzymatically treated or untreated paprika mash. Paprika was comminuted mechanically after which the mash was subjected to either PEF (electric field strength = 1.7 kV/cm, pulse number = 30 and specific energy input per pulse = 0.5 kJ/kg) or a pectolytic enzyme preparation treatment. The extent of cell disintegration after the different pretreatments was monitored through cell disintegration index (Z_p) measurement prior to juice extraction through pressure (10 MPa for 4 min). Some quality parameters (pH, soluble solids (°Brix), total dry matter, color, total carotenoids as β-carotene and vitamin C) of the resultant juice samples were determined. PEF and enzyme treatments resulted in about 10% and 9% increase in juice yield, respectively. Juice from PEF treated paprika compared well in quality with enzyme treated or the untreated. And in some cases such as in color (redness, a value) of the juice, PEF treated had values (+ 18) higher than enzyme treated having + 15.5 and also in the amount of β-carotene extracted into the juice PEF treated juice had more than 60% as compared to about 44% from enzyme treated juice. The pH value for enzyme treated juice was lower than the others.     

THE STIMULATION OF PHENOLICS AND ANTIOXIDANT ACTIVITY IN PEA (PISUM SATIVUM) ELICITED BY GENETICALLY TRANSFORMED ANISE ROOT EXTRACT

A series of dark germination experiments demonstrate the potential of an Agrobacterium rhizogenes‐transformed, high cytokinin root extract of anise (Pimpinella anisum), to stimulate phytophenolic and enhance antioxidant activity in pea (Pisum sativum) seedlings. Average shoot weight increased 40–60% after imbibing seeds for 24 h in a 1.5 to 2.0% extract of the anise root clone AR‐10. Phenolic concentration was positively correlated with shoot weight, suggesting that the total phenolic content was related to seedling vigor. Antioxidant protection factor in pea shoots was also stimulated by AR‐10 extracts. Free proline concentrations were 2–3 times higher in shoots collected from AR‐10 treated peas versus controls. However, proline content also increased as shoot weight declined after being subjected to an overdose of AR‐10 extract in 25% ethanol. G6PDH specific activity, the first committed step of the pentose phosphate pathway, was negatively associated with shoot growth and proline concentrations.     

MODIFICATION OF THE LOW-MOLECULAR WEIGHT BASIC ALBUMIN FRACTION FROM RAPESEED (BRASSICA NAPUS L.) BY ACETYLATION PART 1. CHEMICAL AND PHYSICOCHEMICAL ASPECTS1

The chemical and physicochemical changes of the low-molecular weight basic albumin fraction from rapeseed, as a function of degree of acetylation, were studied using amino and ester groups analyses, PAGE electrophoresis, isoelectric focusing, viscometry, circular dichroism and fluorescence spectroscopy. The surface hydrophobicity was evaluated by means of the ANS fluorescence probe technique. The protein was readily acetylated at the amino groups by addition of acetic anhydride. Acetylation of amino acid hydroxyl groups was significantly slower and proceeded in the presence of an excess of the reagent after the amino groups had already been blocked. Acetylation resulted in protein species with isoelectric points at pH 7.6, 6.6, 5.95 and 5.4. The intrinsic viscosity of the native protein fraction dropped from 0.159 dlg^?1 to 0.038 dlg^?1 at a moderate degree of modification. The secondary structure of the protein, characterized by a content of 40–45% helix conformation, was not significantly influenced by acetylation. Modification did not result in wavelength shifts of the peaks in the near ultraviolet CD and fluorescence spectra. However, the negative ellipticities in the 250–270 nm region of the CD spectrum increased markedly with increasing degree of acetylation. The surface hydrophobicity increased linearly with the amount of acetyl groups introduced into the protein.     

LIPID CONTENT AND FATTY ACID COMPOSITION IN THE GREEN-LIPPED MUSSEL PERNA VIRIDIS (L.)

The lipid content and fatty acid profile in soft tissue of the green-lipped mussel Perna viridis, a widely distributed tropical and subtropical bivalve species, were investigated. The total and neutral lipid contents were 6.17 ± 0.71 and 2.71 ± 0.42 mg per 100 mg dw, respectively. The content of docosahexaenoic acid (DHA, C22:6n-3) was 24.38 ± 2.50 mg/g dw whereas eicosapentaenoic acid (EPA, C20:5n-3) was present at 12.29 ± 2.12 mg/g dw. These two fatty acids were also at the top high percentage among all the fatty acids, with 38.06 ± 0.86% and 17.89 ± 1.24% (w/w) in total lipids and 34.64 ± 2.74% and 20.33 ± 1.05% (w/w) in neutral lipids, respectively. Therefore, green-lipped mussel is a rich source of DHA and EPA, the two n-3 polyunsaturated fatty acids that are beneficial to human health and nutrition.     

DIGESTION OF MYOFIBRILLAR AND SARCOPLASMIC FRACTIONS FROM MENHADEN MUSCLE BY THE ACTION OF MENHADEN (Brevoortia spp.) AND WHITE CROAKER (Micropogonias furnieri) TRYPSINS

Trypsins from the pyloric caeca of menhaden (Brevoortia spp.) and croaker (Micropogonias furnieri) were used for hydrolysis of both myofibrillar and sarcoplasmic fractions from menhaden muscle. Digestion of muscle proteins was carried out at 37C for 20 min with the pH maintained at either 3, 4, 5, 6, 7, 8 or 9; or for 60 min at the pH's of 5, 7, 8 or 9 at 30C and 37C. The hydrolytic action was evaluated based on the concentration of peptides solubilized. Solubility after digestion of myofibrillar, sarcoplasmic fraction and hemoglobin was optimum at basic pH. The sarcoplasmic fraction was solubilized more than the myofibrillar fraction by both fish trypsins. Similar results were obtained with both crude pyloric extracts and purified trypsins from menhaden and white croaker. Thus, the preparation of the crude pyloric caeca may be preferentially used, because of its low cost as well as the simplicity of the preparative procedure .     

MODIFICATIONS IN THE MINERAL CONTENT OF GREEN ASPARAGUS (ASPARAGUS OFFICINALIS, L.) DURING DEVELOPMENT AND PROCESSING (BLANCHING AND CANNING)

Five commercial sizes of green asparagus (fine, middle, thick, very thick and extra thick) were examined at different stages of commercial treatment (blanched and canned) to study possible changes in six minerals (Cu, Zn, Fe, Mn, Ca and Mg) and the ash content. Significant changes were only found in the Fe and Mg content in washed asparagus of different commercial sizes. Blanching must be considered a moderate step because it only modified the levels of the Fe and Ca in some sizes. Canning, however, resulted in a leaching of Cu, Zn, Mn, Fe and Mg, and the up-take of Ca. The size of green asparagus was a source of variation in the Mn, Fe and Ca contents after canning. The highest gains after canning for Ca were detected in the biggest sizes.