Reliable methods for obtaining sterile explants (i. e., that part of the parent plant introduced to in vitro conditions) are critical in tissue culture. Normally, explants are soaked in disinfectants in order to eliminate the coating layer of microorganisms ubiquitously found on plants. This chapter is concerned with the use of mechanical and electronic techniques (i. e., an automated Surface Sterilization System [SSS]) to aid in the sterile establishment of explants. The automated SSS reduces labor input and increases the effectiveness and reproducibility of the surface sterilization treatment (1) (see Fig. 1). Numerous disinfectant types and techniques have been developed to surface sterilize plants (2). However, all procedures can be summarized as follows.

A survey of phenolic compounds using HPLC was performed in Rutaceae, subfamily Aurantioideae, representing five genera, 35 species and 114 cultivars. T

Four different plant growth regulators, gibberellic acid (GA3), naphthaleneacetic acid (NAA), benzyladenine (BA) and abscisic acid (ABA), were individually mixed in a lanolin paste and applied to immature fruit on grapefruit trees beginning soon after fruit set. The treated fruit was allowed to mature on the tree. Application of 1000 ppm GA3 in this manner generally increased fruit size, decreased the concentration of the total acid in the juice and decreased the concentration of naringin in the juice sacs compared to that of the controls. GA3 increased the total soluble solids (brix) in the juice in some experiments. Treatment of fruit with 1000 ppm ABA and BA significantly decreased the size of the fruit and increased the naringin concentration, but had variable effects on the soluble solids content and the acid content. Treatment with 1000 ppm NAA did not produce any significant changes in size, acid content, brix or naringin concentration.

Selected constituents of soft white wheat flour samples from various locations were examined and related to baking quality in order to identify those constituents that are associated with end-use quality. Among the selected constituents, the pentosan fractions were found to be inversely correlated with baking quality. Soluble and enzyme-extractable pentosans were negatively associated with cookie diameter. Cake volume was negatively associated with soluble, enzyme-extractable, and total pentosans.

A malonic acid ester derivative of the flavanone naringin was abundant in the young leaves and fruits of grapefruit plants, but not in the mature leaves and fruits. After isolation, the structure of this compound was established as naringin 6″-malonate (naringenin 72″-O-α-l-rhamnosyl)-β-d-glucoside 6″-malonate).

Radioactively-labeled acetate and phenylalanine were fed to intact and detached tissues of grapefruit seedlings to characterize the biosynthesis and subsequent metabolic fate of the flavanone glycoside naringin. Radiolabeled naringin was biosynthesized from both precursors in detached leaves, but not in detached stems or roots. Young leaves were much more efficient at incorporating label into naringin than older leaves. When radiolabeled precursors were fed to whole seedlings, labeled naringin was found in all parts of the plant, including stems and roots. This suggests that naringin is synthesized in young, rapidly growing leaves, then transported to other parts of the plant.

[14C]Acetate and [14C]phenylalanine were fed to detached immature grapefruit (Citrus paradisi Macfad.) fruits and two radiolabelled flavanone glycosides were detected. TLC analysis and enzymatic hydrolysis studies indicated that the two labelled flavonoids were naringin (naringenin 7-O-β-neohesperidoside) and prunin (naringenin 7-O-β-glucoside). Prunin, which has not been previously shown to be present in grapefruit, was then detected in immature peel. This indicates that immature grapefruits are capable of biosynthesizing flavonoids from simple precursors and suggests that multiple-glycosylation of flavanones may occur by the addition of discrete single sugar units.

Concentrations and HPLC profiles of the major flavonoids of lemon juice vesicles (Citrus limon cv. Eureka) were determined for tree-grown fruit 2–55 mm diameter and in 25–30 mm diameter fruit halves cultured in vitro for up to four months. In tree-grown fruit, the total amount of hesperidin per lemon accumulates rapidly from fruit set to its maximum value at the 25–30 mm diameter stage; and thereafter the concentration continually decreases as the fruit increases in diameter. At the 25–30 mm stage, the total amount of eriocitrin begins to increase rapidly and continues until the fruit reaches full size. The amount of diosmin per fruit increases gradually throughout the development of the lemon. Flavonoids of juice vesicles from in vitro cultured fruit halves show a pattern of development similar to fruit grown on the tree. In contrast, flavonoid patterns from callus derived from juice vesicles were quite dissimilar to those of developing fruit.

An apparatus was constructed that could be used to grow plant tissues, organs, and whole plantlets under sterile conditions. This system accommodated independent or multiple concurrent growth of cultures. Growth of plants either equalled or exceeded that observed using the manual transfer procedure. The automated plant culture system (APCS) consists of silicone tubing, 2 impeller pumps, 2 glass medium reservoir bottles, a 3-way stainless steel valve, a plant culture chamber, and an interface module containing relay boards. Control of the APCS is through interfacing with a microcomputer (e.g. Apple IIe or Atari 400). The computer controlled medium introduction, evacuation, and replenishment in a sterile environment. The APCS was inexpensively constructed and provides a labor-saving, long-term method to culture plants in vitro.

ABSTRACTCorynebacterium fascians cells capable of metabolizing limonoids were prepared conveniently with inexpensive carbon sources such as fructose, galactose and citric acid. Cells thus obtained were immo‐bilized in acrylamide gel and used in a biological debittering process previously developed. The process significantly reduced limonin and nomilin contents of citrus juice sera. It was particularly effective toward the reduction of nomilin. The debittering treatment did not have adverse effects on the composition of other citrus constituents such as citric, malic, ascorbic acids, fructose, glucose and sucrose.

ABSTRACT A microbiological assay used by Vandercook and Smolensky (1976) to measure the content of orange juice in orange drinks was modified for the detection of the adulteration of apple juice by grape juice or water. An assay of 24 samples of retail apple juice, diluted 1:10 revealed little or no growth of Lactobacillus plantarum after 48 hr incubation, whereas solutions containing 8% of the same apple juice and 2% of a retail grape juice had a growth value in absorbance of 0.176 ± 0.039. When samples were supplemented with vitamin‐free casein ammo acids (AHC), bacterial growth increased dramatically in 21 of the juices. Assays run on juice prepared in the laboratory from fresh apples gave the same results, eliminating the possibility that the assay was dependent on the extraction procedure. Solutions of two retail samples of apple juice showed no growth with addition of ammo acids which might indicate that the products were processed differently, were less than single strength, or were “synthetic” juices. One drink mix labelled “artificially flavored” apple cider did not support any growth either. Thus, the adulteration of apple juice with grape juice, overdilution, or use of synthetic products may be detected with the aid of a microbiological assay.

The composition of organic constituents (total sugars, reactive phenols, total amino acids, arginine, and gamma-aminobutyric acid) has been measured in a large (360 samples) selection of concentrated orange juice for manufacturing and orange pulp wash in the U.S. trade. The detection of adulteration with sugar, reducing sugars, and citric acid addition has been investigated by using non-parametric nearest neighbor classification techniques in the 4-space of log ratios of the compositions. The results show that such detection is possible with a type 1=type 2 error rate of 10% for 20% adulteration if at least 7 samples are taken. The assumptions of such samplings are discussed.

Journal of Food ScienceVolume 35, Issue 4 p. 517-518 CHANGES IN ULTRAVIOLET SPECTRAL PROPERTIES OF LEMON JUICE UNDER ADVERSE STORAGE CONDITIONS CARL E. VANDERCOOK, CARL E. VANDERCOOK USDA Western Utilization R&D Div., Fruit and Vegetable Chemistry Lab., Pasadena, Calif. 91106Search for more papers by this author CARL E. VANDERCOOK, CARL E. VANDERCOOK USDA Western Utilization R&D Div., Fruit and Vegetable Chemistry Lab., Pasadena, Calif. 91106Search for more papers by this author First published: July 1970 https://doi.org/10.1111/j.1365-2621.1970.tb00973.xCitations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume35, Issue4July 1970Pages 517-518 RelatedInformation