Development of quick-cooking dehydrated pulses by high temperature short time pneumatic drying

Quick-cooking dehydrated pulses were made from husked split grains of red gram, black gram and Bengal gram using high temperature short time (HTST) pneumatic drying technique wherein porosity was brought about in the dried pulses by exposure of the cooked grains initially to air at a high temperature (170–200°C) for a short duration (4–6 min) in a laboratory model HTST pneumatic drier followed by finish drying at a lower temperature (60–70°C) in a conventional tray or fluidized bed drier. Optimum temperature and time for the HTST drying of the grains were worked out and the HTST dried products were evaluated with respect to their drying behaviour, rehydration characteristics and shelf stability vis-a-vis the conventional hot air dried products.
Considerable reduction in drying and rehydration times could be achieved by the HTST process. The increase in porosity achieved and the HTST treatment did not adversely affect the shelf stability of the grains to any measurable extent.
The technique involves simple equipment and less capital investment as compared to other methods of drying, such as explosive puffing, achieving the same objective. It is amenable to continuous processing as the time of high temperature drying is very short.     

Bacillus subtilis B2产1-脱氧野尻霉素（DNJ）发酵条件优化

为探索制备含有1- 脱氧野尻霉素(1-deoxynojimycin,DNJ)的降血糖功能性食品的新方法,以产DNJ 的菌株Bacillus subtilis B2 为初始菌株,以价廉的农产品加工副产物豆渣为原料,通过对发酵条件的优化,获得富含功能因子DNJ 的发酵液。结果表明：接种量对α- 葡萄糖苷酶抑制活性影响不明显,当接种量大于104 个/mL 时,发酵液的α- 葡萄糖苷酶抑制活性均在20 以上。而豆渣浓度、发酵温度、培养基初始pH 值及发酵时间对发酵液α- 葡萄糖苷酶抑制活性影响较大,在豆渣质量浓度30mg/mL,初始pH 值6～8,发酵温度40℃的条件下发酵48h,发酵液表现出较高的α- 葡萄糖苷酶抑制活性。以Bacillus subtilis B2 发酵豆渣的发酵液为原料开发含DNJ 的降糖功能食品,可以大大提高豆渣的利用价值,为降糖功能食品的开发利用开辟新途径。     

Effects of pulsed electric field on colloidal properties and storage stability of carrot juice

The effects of pulsed electric fields (PEF) and high‐temperature short time (HTST) on the colloidal properties of carrot juice initially after PEF processing and throughout storage period were studied. Compared with HTST treatments, PEF treatments have less effect on the colloidal properties, such as cloud stability, zeta potential, viscosity and particle size distribution (PSD). Pectin methyl esterase (PME) could influence the colloidal properties of carrot juice by de‐esterification of the pectin. In the present work, PME activity was reduced significantly as electric‐field strength (from 15 to 30 kV cm^?1) and treatment time (from 100 to 800 μs) increased. The results also showed that the emergency of a new peak in PSD of samples occurred when the electric intensity exceeded 30 kV cm^?1. Images of transmission electron microscopy showed that particles slightly gathered after PEF treatment. However, under HTST treated, these smaller particles aggregated into net‐like structures that further gathered larger particles. At the micro level, both PEF treated (30 kV cm^?1, 800μs) and HTST treated kept good stability for more than 1 month.     

小黄鱼加工副产物发酵条件的优化及其营养评价

摘 要：目的 为更充分的利用小黄鱼加工副产物, 对酶解处理后的水解产物进行发酵处理。方法 采用响应面分析法优化小黄鱼加工副产物发酵最佳条件。结果 枯草芽孢杆菌发酵最佳条件为发酵时间5 d, 发酵温度29 ℃, 菌种添加量5.3%, 豆粕添加量10.1%, 在此条件下, 小黄鱼加工副产物酶解液发酵后所得氨基酸含量可达39.68 mg/mL。发酵处理后, 发酵液鱼腥味较酶解液明显减轻, 且其碳氮比、乳酸、硝态氮含量显著高于酶解液(P<0.05); 氨基酸总量较酶解液提高27%, 其中苏氨酸、丝氨酸、脯氨酸及甘氨酸等9种氨基酸含量显著提高(P<0.01), 苦味氨基酸天冬氨酸、胱氨酸及精氨酸含量显著降低(P<0.01)。结论 对鱼类副产物酶解液进行进一步发酵处理, 不仅提高了产物的营养水平, 而且更充分的利用水产资源, 提高水产品附加值。     

灵芝发酵芹菜渣条件优化研究

目的获取富含膳食纤维的全营养芹菜汁饮品。方法芹菜渣为芹菜榨汁的副产物,含有芹菜中几乎全部的膳食纤维,利用灵芝发酵产生富含可溶性膳食纤维的发酵液,并对影响其发酵的因素进行初步探索。结果水:芹菜渣为260%(v/w),初始pH5.0,黄豆饼粉1.5%,FeSO4.7H2O 0.008%适于芹菜渣的发酵,发酵产物中可溶性膳食纤维含量可达30.76g/L以上,固形物40.23g/L以上,pH5.0左右,适合与芹菜汁勾兑。结论灵芝发酵芹菜渣所得发酵产品可以弥补芹菜汁中膳食纤维的不足,可获得全营养芹菜汁产品。     

HTST Inactivation of Peroxidase in a Computer-Controlled Reactor

Computer control of the movement of a sample holder and thermocouple into a high temperature steam reactor was found to be an effective system for studying the HTST inactivation of peroxidase. For the kinetic analysis of the heat activation of peroxidase at temperatures above 100°C a fit of the remaining percent of activity to a pseudo-kinetic model which accounted for regeneration was found to give rate constants or D values with a temperature dependence (z value of 33.5°C) in good agreement to data reported earlier.     

EFFECTS OF TYPES AND LEVELS OF FAT AND RATES AND TEMPERATURES OF COMMINUTION ON THE PROCESSING AND CHARACTERISTICS OF FRANKFURTERS

ABSTRACT— Frankfurter emulsions containing either 25% or 35% beef fat, pork fat, or cottonseed oil were prepared by comminuting at 1500, 2500, or 5000 rpm to temperatures ranging from 45°–85°F. Data were obtained on the viscosities of the emulsions; except for initially high viscosities for which unmelted fat was responsible, the viscosities of emulsions containing the fats, or oil, were similar: viscosities tended to decrease with increasing time and temperature of chopping. The frankfurters were stuffed, smoked, and cooked, and data were obtained on shrinkage, fat retention, ease of peeling, specific gravity, and texture. Shrinkage was inversely related to content of fat. Fat separation mainly occurred in processing frankfurters containing beef fat; the data suggest that emulsions containing beef fat should be comminuted to 65°–75°F to avoid possible under or overchopping: the results show that optimum conditions were time as well as temperature dependent. The air content of frankfurters varied inversely with the maximum temperature attained during communition. Frankfurter skin strength was lessened on increasing the temperatures to which emulsions were communited; elasticity, the equivalent of rubberiness, decreased under these conditions.     

Design of conservative simulated particles for validation of a multiphase aseptic process

ABSTRACT:  Simulated food particles with conservative (fast moving and slow heating) properties are required for validation of multiphase aseptic processing for production of shelf-stable low-acid foods. The validation process requires simulated particles to contain residence time tags, thermosensitive implants, and/or bioloads for temperature detection, time–temperature integration, and bactericidal efficacy confirmation. Conservative particle design (CPD) software was used to determine the wall thickness required for conservative behavior of such particles made with polypropylene (PP) and polymethylpentene (PMP) of wall thickness 1 mm (0.0393 inches) and 2 mm (0.0787 inches) containing tube inserts. Thermocouples were inserted in the simulated and real food particles and the particles were heated up to 127 °C under pressurized (24 psi) conditions. Based on the heating rates of the real and simulated particles, an appropriate simulated particle was identified for each type of real food particle. This would allow a food processor to use these designed particles with an appropriate tube insert (diameter) to validate an aseptic process for a multiphase food containing any or all the above tested food materials.     

Flaxseed in Breadmaking: Effects on Sensory Quality, Aging, and Composition of Bakery Products

ABSTRACT:  This paper describes the effect of flaxseed on two bread formulations. The quality of bread rolls—containing flaxseed—and the quality of cinnamon rolls—containing flaxseed and flaxseed oil—is determined by sensory evaluation (texture, odor, and flavor), instrumental texture measurement and chemical analysis (fatty acids, fiber, secoisolarisiresinol diglycoside, and cadmium). Bread aging is monitored by measuring sensory attributes during storage. The results indicate that the flaxseed rolls retain moisture and softness more efficiently than the control rolls that do not contain flaxseed. No off-odors were detected during the storage period from 0 to 6 d at room temperature (+22 °C), although flaxseed rolls and cinnamon rolls were discovered to be high in unsaturated fats. The major fatty acid in both bakery samples that contained flaxseed was α-linolenic acid. The flaxseed rolls were also high in fiber. Therefore, from a nutritional viewpoint flaxseed shows beneficial properties in breadmaking. It has a positive impact on the texture parameters during storage as well as on the nutritional composition, for example, the content of fiber and unsaturated fats.     

Effect of Monascus Fermentation on the Characteristics of Mackerel Mince

ABSTRACT: To improve the characteristics of fish muscle, Monascus purpureus or Monascus species was inoculated in 2.1% rice powder broth containing 30% minced mackerel tissue to produce a fermented fish product. Enterbacteriaceae, Staphylococcus , and Pseudomonas were not present during the 7 d of fermentation at 25 °C. The activities of both amylase and acidic proteases were detected after 1 and 2 d of fermentation, respectively, and further increased during fermentation. The volatile base nitrogen of all Monascus fermented samples were lower than the limit of food regulation in Taiwan (< 25 mg/100 g) even after 7 d of fermentation. Hydrolysis of the muscle protein and accumulation of free amino acid were observed. The fermented fish products had good flavor and color that were highly likeable to the sensory panel.     

Continuous monitoring of yoghurt fermentation using a noble metal electrode array

An electrochemical probe containing gold, platinum and rhodium working electrodes was used to monitor yoghurt production in a pilot facility. Three commercial starting cultures at 40, 42 and 44 °C transformed milk having 1.5% fat content to mild yoghurt products. The electrochemical changes in the broth during fermentation were recorded as current responses from pulse voltammetry over the electrodes. Principal component analysis of the responses generated two-dimensional score plots describing the qualitative fermentation progressions. Two distinct fermentation pathways were observed leading to similar final products. The pH was recorded during the fermentations and the data was used as reference values for creating a partial least squares model for prediction of pH as an example of a quantitative application for the sensor. The relative mean squared error for validation of the model using four probes interchangeably was about 2%. The probe was constructed of materials approved for use in the food industry and did not require a standard glass reference electrode.     

发酵条件对酸樱桃发酵汁挥发性风味物质的影响探究

目的 考察发酵条件对酸樱桃发酵汁中风味物质的影响。方法 利用3株乳酸菌发酵酸樱桃汁, 以pH为指标明确最佳发酵菌种和稀释比例。随后利用气相色谱-离子迁移谱法(gas chromatography-ion mobility spectrometry, GC-IMS)探究糖添加量、pH、氮源、稀释比例对发酵挥发性风味物质的影响。结果 最佳发酵菌为鼠李糖乳杆菌(Lactobacillus GG, LGG), 最佳稀释比例为1:3, 氮源对挥发性风味物质几乎没有影响; 而不同添加量的碳源(葡萄糖)导致发酵液乙偶姻、双乙酰等含量差异; 随着pH增加, 乙偶姻、双乙酰、2-戊酮等含量显著升高; 稀释比例通过影响发酵原汁的浓度导致发酵后风味物质乙偶姻含量显著增加、2-戊酮含量显著降低。进一步差异比对3株乳酸菌酸樱桃发酵汁的风味, 发现LGG代谢脂肪酸可产生较多的2-庚酮及2-戊酮。结论 菌种、糖添加量、稀释比例、起始pH均可导致发酵液中乙偶姻、2-庚酮及2-戊酮等挥发性风味物质产生显著影响, 本研究为酸樱桃的加工利用提供理论指导。     

Quality of applesauces processed by pulsed electric fields and HTST pasteurisation†

A pilot plant scale continuous flow pulsed electric field (PEF) and high temperature short time (HTST) processing system was integrated with an aseptic packaging machine. Fuji applesauce and blueberry applesauce were processed with PEF followed by HTST pasteurisation (PEF + HTST). PEF + HTST processed Fuji applesauce from fresh Fuji apples demonstrated high and stable sensory scores during 9 months storage at 27 °C, and had comparative sensory quality with Meal Read‐to‐Eat (MRE) and commercial applesauce products stored at 4 °C. PEF + HTST processed blueberry applesauce from pre‐pasteurised materials had lower sensory scores than PEF + HTST processed Fuji applesauce and was significantly less stable during the storage at 27 °C. PEF + HTST processed applesauces had aerobic count and mould and yeast count of <10 cfu mL^?1 during storage. Electrical conductivity, pH and °Brix, were not significantly changed throughout storage time (P > 0.05).     

Instant infusion pasteurisation of bovine milk. I. Effects on bacterial inactivation and physical–chemical properties

Two types of milk, skim milk and non-standardised raw milk, were heat treated using direct heating by instant infusion pasteurisation with treatment temperatures in the range from 72°C to 120°C and with holding times of less than 1 second. Indirect heating by HTST pasteurisation (72°C for 15 seconds) was used for comparison. The inactivation of microorganisms reached at least the same level when using instant infusion pasteurisation compared to HTST pasteurisation. Changes in the physical-chemical properties were observed in the skim milk fractions of instant infusion pasteurised non-standardised milk, whereas for instant infusion pasteurised skim milk less influence from the treatments was observed.     

Factors influencing the particle size distribution of flaked meat. I. Effect of temperature, aperture size and prebreaking before flaking

Steer chuck and blade were pre-broken by grinding at −3.0°C and −7.0°C, re-tempered to −3.0°C and −7.0°C, respectively, and then flaked through aperture sizes of 6.1 mm, 9.9 mm or 19.0 mm. Meat was also flaked at −3.0°C without being pre-broken.
More ice melted at the lower temperature; the gain in enthalpy was also higher at −7°C than at −3°C. Size measurements, made using video image analysis, showed that particles produced at the lower temperature had a smaller mean diameter and a greater surface area. Of the three factors investigated, temperature was the most important influence on particle thickness. For a given feed material there was a good correlation between mean diameter and aperture size.
High speed photography results showed that pre-broken meat tended to break-up more readily on the impeller than intact pieces, resulting in pieces of smaller mean diameter.     

高浓高温对啤酒酵母发酵性能的影响

以啤酒酵母S-6为实验菌株,研究了主发酵温度和原麦汁浓度对啤酒发酵的残糖、酒精度、风味物质和絮凝性等性能指标的影响。结果表明,原麦汁浓度一定时,主发酵温度对高级醇和乙酸酯的含量影响较大,主发酵温度由10 ℃提高至16 ℃时,高级醇含量提高了10%～20%,乙酸酯含量提高了8%～16%,但CO2累积质量损失、残糖、酒精度和絮凝性基本不受温度的影响;主发酵温度一定时,原麦汁浓度对酵母絮凝性影响较大,原麦汁浓度越高,酵母絮凝性越低,将高浓（18 °Bx）发酵液稀释50%至常浓（12 °Bx）,残糖、酒精度和高级醇的含量与常浓发酵液基本相同。该研究为选育高温高浓发酵低产高级醇同时强絮凝性酵母菌株提供了重要依据。     

HPLC 法检测HDBRS-1 菌株发酵液中2- 羟基联苯含量

采用高效液相色谱法测定脱硫菌发酵液中2- 羟基联苯(2-HBP)的含量。以Delta-PakTM C18 (300A,3.9mm× 150mm,5μm)为色谱柱,甲醇:水(7:3,V/V)为流动相,流速1ml/min,用紫外检测器在260nm 处检测2-HBP。结果显示2-HBP 标准品的保留时间为2.6min,线性范围为0～80mg/L,利用该方法测得HDBRS-1 菌株发酵液中,2-HBP 的生成量为6.11mg/L。     

进口黑虎虾中霍乱弧菌的鉴定及其挥发性产物分析

目的对进口黑虎虾中分离的菌株F14-2进行种属鉴定,通过顶空气相色谱-质谱联用法(headspace gas chromatography-mass spectrometry,HS-GC-MS)分析分离菌株液态培养代谢的挥发性产物。方法应用VITEK 2 Compact全自动微生物鉴定系统分析菌株的生理生化特征,利用荧光定量PCR特异性扩增检测病原菌,通过顶空气相色谱-质谱联用法分析分离菌株F14-2的代谢的挥发性产物。结果菌株F14-2为革兰氏阴性菌,生理生化特征与霍乱弧菌(Vibrio cholerae)的相似性为98%,荧光定量PCR检测和血清凝集试验进一步确认为非O1非O139群霍乱弧菌,菌株F14-2在营养肉汤(nutrient broth)中代谢的挥发性产物主要有乙醇、异戊醇、乙酸和2-乙基己醇。结论进口黑虎虾中分离的菌株F14-2鉴定为霍乱弧菌,该菌产生的挥发性产物为霍乱弧菌的鉴定提供参考。     

反向高效液相色谱测定发酵液中的聚苹果酸

采用高效液相色谱柱AlltimaTMC18(4.6 mm×150 mm,4μm)上定量测定发酵生产的聚苹果酸,流动相为乙腈和0.025 mol/L磷酸二氢钾混合溶液(磷酸调pH 2.5)(V:V=5:95),流速1.0 mL/min,检测波长210 nm,柱温25℃,进样量5μL。发酵液经离心除菌体、纯沉除多糖、水解处理后进样,可以将其中的L-苹果酸完全分离定量。采用液相方法的回收率为98.70%~100.65%,RSD为0.4~1.11%。采用试剂盒的方法的回收率为96.7~97.23%,RSD为0.57~1.19%。可见,液相的精确度和试剂盒相差不大。但液相的价格相对比试剂盒要便宜很多,说明该法是测定发酵液中聚苹果酸的一种很有效的方法。     

ORGANIC ACID PROFILES OF THERMALLY PROCESSED, STORED SPINACH PUREE

ABSTRACT— Deaerated spinach puree was packed into TDT tubes, flushed with nitrogen and sealed. The tubes were divided into batches and processed with an Fo = 4.9 at temperatures ranging from 240–300°F with 10°F increments. Analyses were carried out immediately after processing and after storage for 3 months at 75°F in the dark. Organic acids were analyzed by means of an Automatic Organic Acid Analyzer (AOAA) with confirmation by paper chromatography. Oxalic acid showed poor resolution on the AOAA; therefore, a chemical method was used for analysis. pH measurements were taken and color measured on a Hunterlab Model D25 Color Difference Meter. Catalase determinations were done on the stored samples. After processing, the greatest changes were noted at 240°F, with only minor changes above 280°F. Acetic and pyrrolidone-carboxylic acid (PCA) showed the most change after processing. After storage, the concentration of acids, color and pH was similar for all packs and all proved catalase negative. During storage succinic, PCA and acetic acids showed the greatest increase with the latter two increasing the most at higher temperatures. Also, during storage α-ketoglutaric acid disappeared and pyruvic, glutaric, oxaloacetic and malonic acids were formed at all processing temperatures.